\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 15:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144957\" href=\"?#comment-144957\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144956\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144957\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144957\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144957\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You don't deal with it for the moment. You deal only with set of positions {1, 5, 6, 7}. Each time, you reduce one or two elements from the set (depending of choosing case 1 or case 2). When set has 0 or 1 element, then you can handle the other positions (see initialization of dp, it will handle position 2 also). As each time K decreases by 1 or 2, it's obvious sometime you'll be in the basic case, when you'll handle the other positions. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144957 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144957 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144957\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144961\" commentParentId=\"144957\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/alibaba\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/alibaba\" title=\"Expert alibaba\" class=\"rated-user user-blue\">alibaba</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 17:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144961\" href=\"?#comment-144961\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144957\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144961\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"97169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144961\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you :D will need time to digest it. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144961 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144961 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144961\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144971\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 23:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144971\" href=\"?#comment-144971\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144971\" revisionCount=\"9\" revision=\"9\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">9</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144971\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144971\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder if the authors will post the solutions to bonus problems after some time? :)</p><p>Anyway, here is my idea of the Div2 A — Bonus, sorry if there is much simpler solution, this is what i thought of :)</p><p>Let's say that the i-th painter will paint all bricks divisible by X[i]. I will assume that the least common multiple of X[1], X[2], X[3]...X[k] will fit in long long. (If it doesn't you can easily still solve it using the same method, it's just for the sake of simplicity). Let's define a certain colouring by a binary number. The <strong>1</strong>s in the binary number correspond to the colors that were surely used ( <strong>0</strong> doesn't necessary mean the colour isn't used ). For example for K=5, 10100 would define that surely the first and third colours were used in that colouring.</p><p>To get the answer we iterate over all possible colourings, and if the colouring contains odd number of ones, we add the amount of bricks that are coloured that way, otherwise we remove that amount. The solution has complexity O(2^k*log) if implemented good, because there are 2^k possible colourings and for each we need to find the least common multiple of the used colours to determine the amount of bricks that are coloured that way.</p><p>I know it sounds quite weird and at the moment i'm struggling to find a proof, but i have tested it and it works. If someone could provide a proof that would be great :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144971 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144971 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144971\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144972\" commentParentId=\"144971\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/04/2013 00:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144972\" href=\"?#comment-144972\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144971\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144972\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144972\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, I'll post my ideas for Bonus tasks if there are enough persons interested. :) This is a classic task solvable by inclusion and exclusion principle. If I understood well what your solution does, it uses exactly this principle. Google it and you'll find proof for your solution :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144972 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144972 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144972\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144974\" commentParentId=\"144972\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/04/2013 00:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144974\" href=\"?#comment-144974\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144972\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144974\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144974\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144974\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'd love to see the solutions, i've spent A LOT of time on those bonus problems :).</p><p>Here is what i consider to be my "proof" for the solution i described above :P</p><p><strong>Proof</strong></p><p>Let's imagine we are iterating the binary numbers in order of increasing amount of ones in them. If we are for example at the number 01010, then we want to count the bricks colored that way, exactly once. However we have already counted them when looking at binary numbers 01000 and 00010. So how many times exactly have we counted a given binary number? Well if the binary number has exactly P ones in it, then we have counted it C(1,P) times when looking at numbers with 1 one in them, C(2,P) times when looking at numbers with 2 ones in them and so on. However remember that we do not always add, we subtract too, so we get the following :</p><p>For a number with P ones in it, we have counted it exactly S times where <strong>S=C(1,P)-C(2,P)+C(3,P)-C(4,P)+C(5,P)...C(P-1,P).</strong></p><p>Well it took me quite a lot of time, but not that difficultly it can be proven that <strong>-C(0,P)+C(1,P)-C(2,P)+C(3,P)...C(P,P) equals 0</strong>, therefor obviously for odd P, S=0 and for even P — S=2. And since we want to count each colouring exactly ones, obviously for odd P, we add it once and for even P we subtract it.</p><p>C(K,N) = <a href=\"https://en.wikipedia.org/wiki/Binomial_coefficient\">binomial coefficient</a></p><p>It's a little bit clumsy but i made it myself because i haven't heard about inclusion-exclusion principle :)</p><p>P.S. Sorry for all those long posts, i just really liked the problems and spent a lot of time on them :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144974 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144974 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144974\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144973\" commentParentId=\"144971\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sparik\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83327/avatar/226632cbc2cf9c5.jpg'/> </a>\n <div><a href=\"/profile/sparik\" title=\"Candidate Master sparik\" class=\"rated-user user-violet\">sparik</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/04/2013 00:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144973\" href=\"?#comment-144973\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144971\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144973\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"83327\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144973\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think this is the simplest solution. It uses inclusion-exclusion principle. <a href=\"http://www.spoj.com/problems/NGM2/\">This problem on SPOJ</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144973 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144973 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144973\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145248\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akshayk0406\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/akshayk0406\" title=\"Pupil akshayk0406\" class=\"rated-user user-green\">akshayk0406</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/09/2013 14:05\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145248\" href=\"?#comment-145248\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145248\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4596\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145248\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem 340C</p><p>I didn't understand second step to calculate sum_of_all_routes. Can someone explain with the help of example.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145248 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145248 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145248\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145285\" commentParentId=\"145248\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Cer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Cer\" title=\"Specialist Cer\" class=\"rated-user user-cyan\">Cer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/09/2013 21:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145285\" href=\"?#comment-145285\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145248\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145285\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145285\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"119611\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145285\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>this step is to compute the sum of all possible differences |ai-aj| where (i != j) in all possible permutations.</p><p>consider we have the sequence a1, a2, a3, a4, a5, a6 and we want to get how many times a2 will come before a3 directly by keeping a1 a4 a5 a6 in this order as a subsequence I will list all those permutations that fullfill the last condition : a2 a3 a1 a4 a5 a6</p><p>a1 a2 a3 a4 a5 a6</p><p>a1 a4 a2 a3 a5 a6</p><p>a1 a4 a5 a2 a3 a6</p><p>a1 a4 a5 a6 a2 a3</p><p>and the number of those permutations is n-1 = 6-1 = 5. and those 5 times is when a1 a4 a5 a6 comes in this order and to compute how many times for all possible orders of a1 a4 a5 a6 then we multiply by (n-2)! = (6-2)! = 4! = 24 so the number of times that a2 a3 comes consecutivly is (n-1)*(n-2)! = (n-1)! and the sum of all differences |a2-a3| is (n-1)!*|a2-a3|. S2 is the sum of all differences |ai - aj| for each i != j .</p><p>to compute S2 : for each ai we want to compute the differece between it and all other elements aj where i != j and let us sort the given sequence a1 a2 a3 a4 a5 a6 in increasing order then the sum of all differences |ai — ak| where k<i is (i-1)*ai — (sum_of_elements_before_position_i) lets call this sum is slefti then we find slefti for each i and let sleft = sleft1 + sleft2 + sleft3 ..... + sleft6 = sum_of(slefti) for i= 1 to n when we compute sleft we find that sright = sleft where sright = sright1 + sright2 + .... + sright6 and we know that S2 = sleft + sright = 2*sleft </p><p>so the last result will be (S1 + S2) / n = (S1 + 2*sleft) / n and to make the fraction in simplest form we divide both of (S1+S2) and n on GCD((s1+s2),n)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145285 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145285 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145285\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145298\" commentParentId=\"145285\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akshayk0406\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/akshayk0406\" title=\"Pupil akshayk0406\" class=\"rated-user user-green\">akshayk0406</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/10/2013 09:05\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145298\" href=\"?#comment-145298\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145285\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145298\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4596\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145298\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks, that was very good explaination. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145298 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145298 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145298\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146123\" commentParentId=\"145285\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lucaspala\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lucaspala\" title=\"Newbie lucaspala\" class=\"rated-user user-gray\">lucaspala</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 08:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146123\" href=\"?#comment-146123\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145285\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146123\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"119656\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146123\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why they are dividing s2 * (n-1)! to n!? Please help me</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146123 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146123 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146123\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145492\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 01:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145492\" href=\"?#comment-145492\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145492\" revisionCount=\"6\" revision=\"6\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">6</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145492\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"15\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145492\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here is my idea on the Div2 B "Can you find maximal area convex quadrilateral", I spent a lot of time on it because it was the only problem that the author didn't have solution for :).</p><p>Its only theoretical, I haven't tested it because I am not able to write source now (I'm currently at the Balkan Olympiad), so if it is wrong please do not hate :)</p><p><strong>My solution</strong></p><p>Ok first, we need to find a way to check if a quadrilateral is convex while constructing it, and to do that we can simply use that quadrilateral's diagonals cross if and only if it's convex. Therefor if we find two crossing lines, created from 4 special points, we have a special convex quadrilateral.</p><p>Now as first step of our algorithm, we will take every two points and construct a line, let the points be A and B, then we will imagine its infinite continuation in the plane, and also two infinite lines perpendicular to our line and crossing it in the special points. That will divide the plane in 6 sections, but for the sake of simplicity we will look only on 3 of them (on one of the sides) because they are simetrical. Here is a picture (special points are red) :</p><p><img alt=\" \" src=\"/predownloaded/04/b2/04b22291765bdf15839e99944b5cddf8f1a31779.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>So we have three zones, blue, green and yellow. Now let's look at all other special points that are in one of those zones. We will do a few rotating sweeping lines to have some ordered sets of points. First sweeping line will start from point A to infinite in direction opposite to B paralel to AB and save all the points in the <strong>BLUE AREA ONLY</strong> , second line will start from point A to infinite being perpendicular to AB and will save all points in the <strong>GREEN AREA ONLY</strong>, third line is the same as the second but starts from B and rotates in the opposite direction, again saves all points in the <strong>GREEN AREA ONLY</strong>, and fourth and last line is same as the first, but start from B and saves all points in the <strong>YELLOW AREA ONLY</strong>. Here is a picture of the lines and their rotating directions :</p><p><img alt=\" \" src=\"/predownloaded/90/a1/90a16ea1ffdaec788c2b32e2c5c7fcb63738809b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>For each special point we will save the cross product it gives with line AB. So for each line we have four sets of points where the second and third actually contain the same points but with different orderings. We put those 4 sets in 4 RMQ structures so we could later get the highest of the cross products in some interval fast. Assuming we use roughly O(N*LOGN) for the sweeping lines and to build RMQ, and O(N^2) to fix a line, we have complexity of O(N^3*LOGN) for now.</p><p>Now let's proceed with our actual solution. We fix a line AB and a third point C. Now we want such point D so that AB and CD cross (being the diagonals of convex quadrilateral) and the cross product of D to the line AB is maximum. Let's look at a picture of points A,B and C :</p><p><img alt=\" \" src=\"/predownloaded/11/e9/11e9e5f8f9e2a5ad97396fb10016de0db20efdad.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Obviously for CD to cross AB, D must be in the area marked with white above. So now how to fast get the point with maximum cross product to AB in that white area? Well we have 3 different cases depending on the place of C in the initial 6 zones that I divided the plane into. Let's take a look.</p><p><strong>Case 1</strong></p><p>When C is on the other side of the <strong>blue area</strong></p><p><img alt=\" \" src=\"/predownloaded/8d/e1/8de155f6e990f50da4bd43c1d85ab26eca1c08e2.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>So obviously we want D to be in the pink area, pink area covers part of the green and part of the yellow areas. For the green area we can use the set of points from sweeping line 2. By binary we will find the first point that is in the pink area, and then get RMQ query for that suffix of the array of points. Same thing we can do with the yellow area, using the points from sweeping line 4. Therefor we can find the best point D in O(LOGN).</p><p><strong>Case 2</strong></p><p>When C is on the other side of the <strong>green area</strong></p><p><img alt=\" \" src=\"/predownloaded/09/73/09733f3479756bb9177f87b4ac6a78b0baa06449.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Now obviously we cover the whole green area, so we can just call a RMQ query of the whole range on any of the sweeping line 2 or 3, and for the blue part that is covered, we can again do binary and then RMQ query in points from sweep line 1, and the same thing for the yellow parts, with the points from sweep line 4.</p><p><strong>Case 3</strong></p><p>When C is on the other side of the <strong>yellow area</strong></p><p>I'm not gonna show a picture of that as it is really symmetrical to case 1, you just again use binary and RMQ query in sweep lines 1 and 3 for the blue and green parts that are covered.</p><p>Obviously each test case takes roughly O(LOGN) and fixing points A,B,C is O(N^3), so i think that solution would be O(N^3*LOGN) in general. I'm sorry if it is wrong i am unable to test it right now, but I really took a lot of time to explain it nicely (sorry if it isn't very understandable), so hope I helped :)</p><p>P.S. Sorry for the long post, I was excited to share my idea :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145492 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145492 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145492\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145493\" commentParentId=\"145492\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sweiss\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/sweiss\" title=\"Grandmaster sweiss\" class=\"rated-user user-red\">sweiss</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 01:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145493\" href=\"?#comment-145493\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145492\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145493\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"412\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145493\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>dude, you're awesome!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145493 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145493 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145493\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145496\" commentParentId=\"145492\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 01:44\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145496\" href=\"?#comment-145496\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145492\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145496\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145496\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Isn't the author's solution <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">3</sup>)</span>?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145496 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145496 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145496\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145497\" commentParentId=\"145496\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 01:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145497\" href=\"?#comment-145497\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145496\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145497\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145497\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145497\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Author's solution describes a solution for finding maximal area quadrilateral, however it doesn't guarantee it will be a convex one. In the bonus tasks the author asked if anyone could find a maximal area <strong>convex</strong> quadrilateral in less than O(N^4), because he couldn't find a solution, and I took it as a challenge. It is a bonus task :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145497 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145497 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145497\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145498\" commentParentId=\"145497\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 02:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145498\" href=\"?#comment-145498\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145497\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145498\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145498\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah, right. I didn't notice that. Seems quite tough to implement... well done.</p><p>And a challenge atop a challenge: yesterday's gym ACM training, problem I: find the largest convex <strong>polygon</strong> which doesn't contain any of additional specified points (vertices in "red" points, doesn't contain any "blue" points).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145498 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145498 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145498\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145605\" commentParentId=\"145492\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 21:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145605\" href=\"?#comment-145605\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145492\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145605\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145605\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>By the way, one could use only two sweeping lines (merging 1 with 2 and 3 with 4, but you would need two binary searches for determining both ends of the interval to query about.</p><p>Also a question to the author, when you say "find a convex polygon very very fast", what complexity do you mean? The input is O(N) so I guess it's above that, but is it like O(NLOGN) or O(N^2)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145605 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145605 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145605\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145619\" commentParentId=\"145605\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 22:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145619\" href=\"?#comment-145619\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145605\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145619\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145619\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145619\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Your solution to Bonus task B is really nice :) Good job. I added it to the post.</p><p>You have to find a convex quadrilateral, not a convex polygon. And yes, this one can be done very very quick. To be precise, no matter how big is N, you can find a convex quadrilateral in O(1). Suppose you have to read also the set of points, the complexity is still O(1). I hope it does not spoil too much :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145619 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145619 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145619\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145790\" commentParentId=\"145619\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2013 23:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145790\" href=\"?#comment-145790\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145619\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145790\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145790\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I got it!</p><p>Among any 5 points (with any 3 non-collinear, so there are no degenerate cases), there are some 4 which form a convex quadrilateral.</p><p>Suppose we take just 4 points. Either they form a convex quadrilateral, or there's one point (P4) that's inside the triangle T (with vertices P1..3) formed by the other 3. Now, take that case.</p><p>A quad. is convex iff its diagonals intersect. So if the 5th point (P5) is outside T, then one of the triangle's sides and segment P4-P5 intersect, so there's a convex quad. defined by them.</p><p>Now, take the situation when the P5 is inside T, which is split by P4 into 3 smaller triangles (by segments P1-P4, P2-P4, P3-P4). P5 must be in one of them (w.l.o.g. in P1P2P4). And again, the segment P3-P5 must cross one of the segments P1-P4 and P2-P4, so we have a convex quadrilateral.</p><p>What we need to do is: read the first 5 points of the list, try all possible quadrilaterals formed by them and check which one (there may be more than 1, but we only need one) is convex. Since we work on N=5, time is O(1). Tada!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145790 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145790 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145790\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145792\" commentParentId=\"145790\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2013 23:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145792\" href=\"?#comment-145792\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145790\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145792\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145792\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yep, this is the solution :)</p><p>Anyway, this is a Ramsey theory problem, which was studied for convex N-gons also. You can read details <a href=\"https://en.wikipedia.org/wiki/Happy_Ending_problem\">here</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145792 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145792 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145792\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145807\" commentParentId=\"145792\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 00:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145807\" href=\"?#comment-145807\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145792\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145807\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145807\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ooh, the generalization's nice! This will go to a slovak math training for sure (hehehe, let them suffer :D)!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145807 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145807 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145807\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146062\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lucaspala\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lucaspala\" title=\"Newbie lucaspala\" class=\"rated-user user-gray\">lucaspala</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 21:04\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146062\" href=\"?#comment-146062\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146062\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"119656\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146062\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Regarding problem C |ai - aj| for each i != j by S2, the answer is (N – 1)! * S1 + (N – 1)! * S2 / N!. In this formula i didn't understand that why they divide to N!. I will be pleasant if someone helps me.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146062 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146062 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146062\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146127\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Phicar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48358/avatar/9b2275bdec5496ef.jpg'/> </a>\n <div><a href=\"/profile/Phicar\" title=\"Pupil Phicar\" class=\"rated-user user-green\">Phicar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 09:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146127\" href=\"?#comment-146127\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146127\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48358\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146127\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can use Inclusion Exclusion without all that stuff, just using the number of -1's that appeared and the number of numbers that may be fixed points...just do the math as you want to compute the derrangements and you would get something like: </p><p><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1439932beeefe50c45c12a6529cdd88165b78e99.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> where n is the number of -1's and m is the number of positions that can be fixed points(the ones that have a -1 and it's index is not already used)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146127 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146127 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146127\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147926\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/crookshanks\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/89212/avatar/139d67c85696cc59.jpg'/> </a>\n <div><a href=\"/profile/crookshanks\" title=\"Specialist crookshanks\" class=\"rated-user user-cyan\">crookshanks</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/10/2013 11:02\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147926\" href=\"?#comment-147926\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147926\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"89212\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147926\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>this is gotta be the best tutorial of any contest of #CF ..... very nice :D (Y)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147926 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147926 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147926\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"155448\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Vadim2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49195/avatar/6b6e0d05659bf599.jpg'/> </a>\n <div><a href=\"/profile/Vadim2\" title=\"Expert Vadim2\" class=\"rated-user user-blue\">Vadim2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/25/2013 16:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-155448\" href=\"?#comment-155448\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"155448\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49195\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-155448\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have a qustion for B div2. Is it true, that 4 dots in the answer will be the part of convex hull?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-155448 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-155448 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-155448\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"157979\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sbasrik\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/25889/avatar/3cac1cfe4afcc819.jpg'/> </a>\n <div><a href=\"/profile/sbasrik\" title=\"Expert sbasrik\" class=\"rated-user user-blue\">sbasrik</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/16/2014 23:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-157979\" href=\"?#comment-157979\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"157979\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"25889\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-157979\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could anyone explain why "A number A[x][y] appears in exactly (X – x + 1) * (Y – y + 1) terms of xor sum." in Div1D problem ? What does "formula (X – x + 1)*(Y – y + 1) " mean, how we find it ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-157979 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-157979 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-157979\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"157987\" commentParentId=\"157979\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/17/2014 00:02\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-157987\" href=\"?#comment-157987\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-157979\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"157987\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-157987\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You're interested, for each element A[x][y], how many submatrixes it influences. So, if by (1, 1, a, b) I denote xor sum of all elements in submatrix (1, 1, a, b), how many (1, 1, a, b) do contain cell (x, y)?</p><p>You can see a submatrix (1, 1, a, b) contains cell (x, y) if a >= x and b >= y. So a can be in set {x, x + 1, ...., X} and b can be in set {y, y + 1, ..., Y}. First set contains X — x + 1 values and second one contains Y — y + 1 values. Choosing a and b is independent, even if I fix an a, the b can still take any value. Using rule of product, you get the number of matrixes (1, 1, a, b) which contain (x, y) is (X — x + 1) * (Y — y + 1).</p><p>Let cnt be number of submatrixes (1, 1, a, b) which contain (x, y). If cnt is even, number cancel each other in xor sum, so no need to xor A[x][y]. If cnt is odd, exactly one A[x][y] will remain, other cnt — 1 will cancel each other, since cnt — 1 is even number.</p><p>Now saying for each cell (x, y) you xor-ed value A[x][y] each time (x, y) appears in a submatrix (1, 1, a, b) is equivalent to say for each submatrix (1, 1, a, b) you xor-ed values of all elements it contains. Is it clear why? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-157987 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-157987 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-157987\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158007\" commentParentId=\"157987\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sbasrik\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/25889/avatar/3cac1cfe4afcc819.jpg'/> </a>\n <div><a href=\"/profile/sbasrik\" title=\"Expert sbasrik\" class=\"rated-user user-blue\">sbasrik</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/17/2014 01:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158007\" href=\"?#comment-158007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-157987\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"25889\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, now it is pretty clear, I got it exactly. Thanks a lot for spending time to explain it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"208781\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mochow\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/93201/avatar/bd3960384748e28.jpg'/> </a>\n <div><a href=\"/profile/mochow\" title=\"Specialist mochow\" class=\"rated-user user-cyan\">mochow</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2015 01:43\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-208781\" href=\"?#comment-208781\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"208781\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"93201\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-208781\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for this great tutorial. I am very satisfied specially at problem E of div2. The problem was fun. And so the dp solution was. :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-208781 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-208781 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-208781\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"255114\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/satyam\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/satyam\" title=\"Expert satyam\" class=\"rated-user user-blue\">satyam</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/07/2015 10:01\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-255114\" href=\"?#comment-255114\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"255114\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"136753\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-255114\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think there's a minor error in BubbleSortGraph's problem statement and editorial:</p><p>It is written:</p><p><code>if a[i] > a[i + 1] then add an undirected edge in G between a[i] and a[i + 1]</code></p><p>But, the edge should be between indexes i and i+1 instead of a[i] and a[i+1], consider this example:</p><p>2 3 2 6 8</p><p>The LIS here is: 2 3 6 8 , but there's an edge between 3 and 2 as indexes 2 and 3 are an inversion.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-255114 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-255114 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-255114\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"255140\" commentParentId=\"255114\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/satyam\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/satyam\" title=\"Expert satyam\" class=\"rated-user user-blue\">satyam</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/07/2015 12:41\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-255140\" href=\"?#comment-255140\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-255114\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"255140\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"136753\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-255140\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry, it's correct. I didn't notice that the elements are distinct.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-255140 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-255140 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-255140\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"366009\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/parthlathiya\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/256087/avatar/b8298fb0719d686.jpg'/> </a>\n <div><a href=\"/profile/parthlathiya\" title=\"Expert parthlathiya\" class=\"rated-user user-blue\">parthlathiya</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2017 03:46\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-366009\" href=\"?#comment-366009\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"366009\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"366009\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-10\"\r\n data-commentUserId=\"256087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-366009\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For 340D Bubble Sort Graph: <strong>Simple</strong> algoritham for LIS (Time complexity — O(nlogn) ) — Without using binary indexed tree,you just need to maintain one array. <a href=\"http://www.geeksforgeeks.org/longest-monotonically-increasing-subsequence-size-n-log-n/\">http://www.geeksforgeeks.org/longest-monotonically-increasing-subsequence-size-n-log-n/</a></p><p>Why downvotes?</p><p>My accepted solution using LIS(TC: nlogn), Without using binary indexed tree, <a href=\"//codeforces.com/contest/340/submission/27713075\">http://codeforces.com/contest/340/submission/27713075</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-366009 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-366009 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-366009\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"389733\" commentParentId=\"366009\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sagarthecoder2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/496991/avatar/61d8d75ce582d9ea.jpg'/> </a>\n <div><a href=\"/profile/sagarthecoder2\" title=\"Specialist sagarthecoder2\" class=\"rated-user user-cyan\">sagarthecoder2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/07/2017 19:39\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-389733\" href=\"?#comment-389733\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-366009\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"389733\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"496991\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-389733\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I couldn't understand,how 340D is related to longest increasing subsequence??? please reply me clearly .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-389733 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-389733 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-389733\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"389749\" commentParentId=\"389733\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/parthlathiya\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/256087/avatar/b8298fb0719d686.jpg'/> </a>\n <div><a href=\"/profile/parthlathiya\" title=\"Expert parthlathiya\" class=\"rated-user user-blue\">parthlathiya</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/07/2017 21:21\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-389749\" href=\"?#comment-389749\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-389733\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"389749\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"256087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-389749\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Read lemma 2 in above editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-389749 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-389749 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-389749\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"512615\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/praveenojha33\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/687087/avatar/f4330bc8d9012dda.jpg'/> </a>\n <div><a href=\"/profile/praveenojha33\" title=\"Expert praveenojha33\" class=\"rated-user user-blue\">praveenojha33</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2019 23:28\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-512615\" href=\"?#comment-512615\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"512615\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"687087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-512615\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In question B, Maximum Area Quadrilateral, Can anyone explain the solution more clearly ( The image in editorial is also unavailable ) specially the corner case. Thank You</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-512615 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-512615 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-512615\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8826\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8826 = true;\r\nvar lastPreviewContent8826 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8826] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8826] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8810\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8810, _tta: Codeforces.tta(), topicRevisionId: 31487, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8810\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8810, _tta: Codeforces.tta(), topicRevisionId: 31487, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:20</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128747b98c775b3',t:'MTY5NjcwNTk0MC4yMTkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1730,"cells":{"problem_id":{"kind":"string","value":"341D"},"contest":{"kind":"string","value":"341"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Iahub and Xors"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Iahub and Xors</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub does not like background stories, so he'll tell you exactly what this problem asks you for.</p><p>You are given a matrix <span class=\"tex-span\"><i>a</i></span> with <span class=\"tex-span\"><i>n</i></span> rows and <span class=\"tex-span\"><i>n</i></span> columns. Initially, all values of the matrix are zeros. Both rows and columns are 1-based, that is rows are numbered 1, 2, ..., <span class=\"tex-span\"><i>n</i></span> and columns are numbered 1, 2, ..., <span class=\"tex-span\"><i>n</i></span>. Let's denote an element on the <span class=\"tex-span\"><i>i</i></span>-th row and <span class=\"tex-span\"><i>j</i></span>-th column as <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i>, <i>j</i></sub></span>.</p><p>We will call a submatrix <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">0</sub>, <i>y</i><sub class=\"lower-index\">0</sub>, <i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>)</span> such elements <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i>, <i>j</i></sub></span> for which two inequalities hold: <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub> ≤ <i>i</i> ≤ <i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">0</sub> ≤ <i>j</i> ≤ <i>y</i><sub class=\"lower-index\">1</sub></span>.</p><p>Write a program to perform two following operations:</p><ol> <li> Query(<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">0</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub></span>): print the xor sum of the elements of the submatrix <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">0</sub>, <i>y</i><sub class=\"lower-index\">0</sub>, <i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>)</span>. </li><li> Update(<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">0</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>v</i></span>): each element from submatrix <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">0</sub>, <i>y</i><sub class=\"lower-index\">0</sub>, <i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>)</span> gets xor-ed by value <span class=\"tex-span\"><i>v</i></span>. </li></ol></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers: <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 1000</span>) and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup></span>). The number <span class=\"tex-span\"><i>m</i></span> represents the number of operations you need to perform. Each of the next <span class=\"tex-span\"><i>m</i></span> lines contains five or six integers, depending on operation type. </p><p>If the <span class=\"tex-span\"><i>i</i></span>-th operation from the input is a query, the first number from <span class=\"tex-span\"><i>i</i></span>-th line will be 1. It will be followed by four integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">0</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub></span>. If the <span class=\"tex-span\"><i>i</i></span>-th operation is an update, the first number from the <span class=\"tex-span\"><i>i</i></span>-th line will be 2. It will be followed by five integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">0</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>v</i></span>. </p><p>It is guaranteed that for each update operation, the following inequality holds: <span class=\"tex-span\">0 ≤ <i>v</i> < 2<sup class=\"upper-index\">62</sup></span>. It is guaranteed that for each operation, the following inequalities hold: <span class=\"tex-span\">1 ≤ <i>x</i><sub class=\"lower-index\">0</sub> ≤ <i>x</i><sub class=\"lower-index\">1</sub> ≤ <i>n</i></span>, <span class=\"tex-span\">1 ≤ <i>y</i><sub class=\"lower-index\">0</sub> ≤ <i>y</i><sub class=\"lower-index\">1</sub> ≤ <i>n</i></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each query operation, output on a new line the result.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 5<br/>2 1 1 2 2 1<br/>2 1 3 2 3 2<br/>2 3 1 3 3 3<br/>1 2 2 3 3<br/>1 2 2 3 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/>2<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>After the first <span class=\"tex-span\">3</span> operations, the matrix will look like this: </p><pre class=\"verbatim\"><br/>1 1 2<br/>1 1 2<br/>3 3 3<br/></pre><p>The fourth operation asks us to compute 1 xor 2 xor 3 xor 3 = 3.</p><p>The fifth operation asks us to compute 1 xor 3 = 2. </p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"238cf4925e8bca13c41954e22f6d0d93\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"fb99ade5650f069f8c493acef1270657c082b773\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='238cf4925e8bca13c41954e22f6d0d93'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F341%2Fproblem%2FD%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='238cf4925e8bca13c41954e22f6d0d93'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/341\">Codeforces Round 198 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='238cf4925e8bca13c41954e22f6d0d93'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/341/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Heaps, binary search trees, segment trees, hash tables, etc\">\r\n data structures\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2500\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='238cf4925e8bca13c41954e22f6d0d93'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3425\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='238cf4925e8bca13c41954e22f6d0d93'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3425\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8748\" title=\"Codeforces Round #198\" target=\"_blank\">Codeforces Round #198</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1830:1831\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/8755\" title=\"Tutorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1835\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/341\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/341/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/341/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/341/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/341/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/341/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/341/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/341/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_2c51ecf1facd30f49cfae1d433de7a3e11c5360e\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Iahub and Xors</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub does not like background stories, so he'll tell you exactly what this problem asks you for.</p><p>You are given a matrix <span class=\"tex-span\"><i>a</i></span> with <span class=\"tex-span\"><i>n</i></span> rows and <span class=\"tex-span\"><i>n</i></span> columns. Initially, all values of the matrix are zeros. Both rows and columns are 1-based, that is rows are numbered 1, 2, ..., <span class=\"tex-span\"><i>n</i></span> and columns are numbered 1, 2, ..., <span class=\"tex-span\"><i>n</i></span>. Let's denote an element on the <span class=\"tex-span\"><i>i</i></span>-th row and <span class=\"tex-span\"><i>j</i></span>-th column as <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i>, <i>j</i></sub></span>.</p><p>We will call a submatrix <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">0</sub>, <i>y</i><sub class=\"lower-index\">0</sub>, <i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>)</span> such elements <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i>, <i>j</i></sub></span> for which two inequalities hold: <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub> ≤ <i>i</i> ≤ <i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">0</sub> ≤ <i>j</i> ≤ <i>y</i><sub class=\"lower-index\">1</sub></span>.</p><p>Write a program to perform two following operations:</p><ol> <li> Query(<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">0</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub></span>): print the xor sum of the elements of the submatrix <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">0</sub>, <i>y</i><sub class=\"lower-index\">0</sub>, <i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>)</span>. </li><li> Update(<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">0</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>v</i></span>): each element from submatrix <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">0</sub>, <i>y</i><sub class=\"lower-index\">0</sub>, <i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>)</span> gets xor-ed by value <span class=\"tex-span\"><i>v</i></span>. </li></ol></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers: <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 1000</span>) and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup></span>). The number <span class=\"tex-span\"><i>m</i></span> represents the number of operations you need to perform. Each of the next <span class=\"tex-span\"><i>m</i></span> lines contains five or six integers, depending on operation type. </p><p>If the <span class=\"tex-span\"><i>i</i></span>-th operation from the input is a query, the first number from <span class=\"tex-span\"><i>i</i></span>-th line will be 1. It will be followed by four integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">0</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub></span>. If the <span class=\"tex-span\"><i>i</i></span>-th operation is an update, the first number from the <span class=\"tex-span\"><i>i</i></span>-th line will be 2. It will be followed by five integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">0</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>v</i></span>. </p><p>It is guaranteed that for each update operation, the following inequality holds: <span class=\"tex-span\">0 ≤ <i>v</i> < 2<sup class=\"upper-index\">62</sup></span>. It is guaranteed that for each operation, the following inequalities hold: <span class=\"tex-span\">1 ≤ <i>x</i><sub class=\"lower-index\">0</sub> ≤ <i>x</i><sub class=\"lower-index\">1</sub> ≤ <i>n</i></span>, <span class=\"tex-span\">1 ≤ <i>y</i><sub class=\"lower-index\">0</sub> ≤ <i>y</i><sub class=\"lower-index\">1</sub> ≤ <i>n</i></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each query operation, output on a new line the result.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 5<br />2 1 1 2 2 1<br />2 1 3 2 3 2<br />2 3 1 3 3 3<br />1 2 2 3 3<br />1 2 2 3 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br />2<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>After the first <span class=\"tex-span\">3</span> operations, the matrix will look like this: </p><pre class=\"verbatim\"><br />1 1 2<br />1 1 2<br />3 3 3<br /></pre><p>The fourth operation asks us to compute 1 xor 2 xor 3 xor 3 = 3.</p><p>The fifth operation asks us to compute 1 xor 3 = 2. </p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:24</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bd359fa73374',t:'MTY5NjY0NjAwNC4xNzYwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Heaps, binary search trees, segment trees, hash tables, etc\"]"},"short_tags":{"kind":"string","value":"[\"data structures\", \"*2500\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8755"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"63d3318cfac089ece0c498e9cb121ecd\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #198 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #198 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='63d3318cfac089ece0c498e9cb121ecd'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8755\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='63d3318cfac089ece0c498e9cb121ecd'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:41</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:41</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='63d3318cfac089ece0c498e9cb121ecd'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/fchirica\">fchirica</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/fchirica\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/fchirica\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/fchirica\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/fchirica\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/fchirica\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/fchirica\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/fchirica\" style=\"text-decoration:none;color:black !important;\">fchirica's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8810\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8755\"> <p>Codeforces Round #198 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a>,\r\n <span class=\"format-humantime\" title=\"Aug/30/2013 23:23\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h2><a href=\"/contest/340/problem/A\" title=\"Codeforces Round 198 (Div. 2)\">340A - The Wall</a></h2><p>You are given a range <span class=\"tex-span\">[<i>A</i>, <i>B</i>]</span>. You're asked to compute fast how many numbers in the range are divisible by both <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>. I'll present here an <span class=\"tex-span\"><i>O</i>(<i>log</i>(<i>max</i>(<i>x</i>, <i>y</i>))</span> solution. We made tests low so other not optimal solutions to pass as well. The solution refers to the original problem, where <span class=\"tex-span\"><i>x</i>, <i>y</i> ≤ 10<sup class=\"upper-index\">9</sup></span>. </p><p>Firstly, we can simplify the problem. Suppose we can calculate how many numbers are divisible in range <span class=\"tex-span\">[1, <i>X</i>]</span> by both <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>. Can this solve our task? The answer is yes. All numbers in range <span class=\"tex-span\">[1, <i>B</i>]</span> divisible by both numbers should be counted, except the numbers lower than <span class=\"tex-span\"><i>A</i></span> (1, 2, ..., A — 1). But, as you can see, numbers lower than A divisible by both numbers are actually numbers from range [1, A — 1]. So the answer of our task is f(B) — f(A — 1), where f(X) is how many numbers from 1, 2, ..., X are divisible by both x and y.</p><p>For calculate in <span class=\"tex-span\"><i>O</i>(<i>log</i>(<i>max</i>(<i>x</i>, <i>y</i>))</span> the f(X) we need some math. If you don't know about it, please read firstly about least common multiple. Now, what will be the lowest number divisible by both x and y. The answer is least common multiple of x and y. Let's note it by <span class=\"tex-span\"><i>M</i></span>. The sequence of the numbers divisible by both x and y is <span class=\"tex-span\"><i>M</i></span>, <span class=\"tex-span\">2 * <i>M</i></span>, <span class=\"tex-span\">3 * <i>M</i></span> and so on. As a proof, suppose a number z is divisible by both x and y, but it is not in the above sequence. If a number is divisible by both x and y, it will be divisible by M also. If a number is divisible by M, it will be in the above sequence. Hence, the only way a number to be divisible by both x and y is to be in sequence <span class=\"tex-span\"><i>M</i></span>, <span class=\"tex-span\">2 * <i>M</i></span>, <span class=\"tex-span\">3 * <i>M</i></span>, ...</p><p>The f(X) calculation reduces to finding the number of numbers from sequence <span class=\"tex-span\"><i>M</i></span>, <span class=\"tex-span\">2 * <i>M</i></span>, <span class=\"tex-span\">3 * <i>M</i></span>, ... lower or equal than X. It's obvious that if a number h * M is greater than X, so will be (h + 1) * M, (h + 2) * M and so on. We actually need to find the greatest integer number h such as <span class=\"tex-span\"><i>h</i> * <i>M</i> ≤ <i>X</i></span>. The numbers we're looking for will be <span class=\"tex-span\">1 * <i>M</i>, 2 * <i>M</i>, ..., <i>h</i> * <i>M</i></span> (so their count will be <span class=\"tex-span\"><i>h</i></span>). The number h is actually [X / M], where [number] denotes the integer part of [number]. Take some examples on paper, you'll see why it's true.</p><p>The only thing not discussed is how to calculate the number M given 2 number x and y. You can use this formula <span class=\"tex-span\"><i>M</i> = <i>x</i> * <i>y</i> / <i>gcd</i>(<i>x</i>, <i>y</i>)</span>. For calculate gcd(x, y) you can use Euclid's algorithm. Its complexity is <span class=\"tex-span\"><i>O</i>(<i>log</i>(<i>max</i>(<i>x</i>, <i>y</i>))</span>, so this is the running time for the entire algorithm. </p><p>Official solution: <a href=\"/contest/340/submission/4383403\" title=\"Submission 4383403 by fchirica\">4383403</a></p><h2><a href=\"/contest/340/problem/B\" title=\"Codeforces Round 198 (Div. 2)\">340B - Maximal Area Quadrilateral</a></h2><p>I want to apologize for not estimating the real difficulty of this task. It turns out that it was more complicated than we thought it might be. Let's start explanation.</p><p>Before reading this, you need to know what is signed area of a triangle (also called cross product or ccw function). Without it, this explanation will make no sense. </p><p>The first thing we note is that a quadrilateral self intersecting won't have maximum area. I'll show you this by an image made by my "talents" in Paint :) As you can see, if a quadrilateral self intersects, it can be transformed into one with greater area. </p><p><img alt=\" \" src=\"/predownloaded/0e/1b/0e1b599b731a7c44948324132a0282ab4de2d724.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Each quadrilateral has 2 diagonals: connecting 1st and 3rd point and connecting 2nd and 4th point. A diagonal divides a plane into 2 subplanes. Suppose diagonal is AB. A point X can be in one of those two subplanes: that making cross product positive and that making cross product negative. A point is in "positive" subplane if ccw(X, A, B) > 0 and in "negative" subplane ccw(X, A, B) < 0. Note that according to the constraints of the task, ccw(X, A, B) will never be 0.</p><p>Let's make now the key observation of the task. We have a quadrilateral. Suppose AB is one of diagonals and C and D the other points from quadrilateral different by A and B. If the current quadrilateral could have maximal area, then one of points from C and D needs to be in "positive subplane" of AB and the other one in "negative subplane". What would happen if C and D will be in the same subplane of AB? The quadrilateral will self intersect. If it will self intersect, it won't have maximal area. "A picture is worth a thousand words" — this couldn't fit better in this case :) Note that the quadrilateral from the below image is A-C-B-D-A.</p><p><img alt=\" \" src=\"https://imageshack.us/a/img42/9976/dwkn.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Out task reduces to fix a diagonal (this taking O(N ^ 2) time) and then choose one point from the positive and the negative subplane of the diagonal. I'll say here how to choose the point from the positive subplane. That from negative subplane can be chosen identically. The diagonal and 3rd point chosen form a triangle. As we want quadrilateral to have maximal area, we need to choose 3rd point such as triangle makes the maximal area. As the positive and negative subplanes are disjoint, the choosing 3rd point from each of them can be made independently. Hence we get O(N ^ 3) complexity. A tricky case is when you choose a diagonal but one of the subplanes is empty. In this case you have to disregard the diagonal and move to the next one. </p><p>Official solution: <a href=\"/contest/340/submission/4383413\" title=\"Submission 4383413 by fchirica\">4383413</a></p><h2><a href=\"/contest/340/problem/C\" title=\"Codeforces Round 198 (Div. 2)\">340C - Tourist Problem</a></h2><p>Despite this is a math task, the only math formula we'll use is that number of permutations with <span class=\"tex-span\"><i>n</i></span> elements is <span class=\"tex-span\"><i>n</i>!</span>. From this one, we can deduce the whole task.</p><p>The average formula is sum_of_all_routes / number_of_routes. As each route is a permutation with n elements, number_of_routes is <span class=\"tex-span\"><i>n</i>!</span>. Next suppose you have a permutation of a: p1, p2, …, pn. The sum for it will be p1 + |p2 – p1| + … + |pn – pn-1|. The sum of routes will be the sum for each possible permutation. </p><p>We can calculate sum_of_all routes in two steps: first time we calculate sums like “p1” and then we calculate sums like “|p2 – p1| + … + |pn – pn-1|” for every existing permutation. </p><p><strong>First step</strong> Each element of <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, …, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> can appear on the first position on the routes and needs to be added as much as it appears. Suppose I fixed an element X for the first position. I can fill positions 2, 3, .., n – 1 in (n – 1)! ways. Why? It is equivalent to permuting n – 1 elements (all elements except X). So sum_of_all = <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span> * (n – 1)! + <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span> * (n – 1)! + … * <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> * (n – 1)! = (n – 1)! * (<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span> + <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span> + … + <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>).</p><p><strong>Second step</strong> For each permutation, for each position j between 1 and n – 1 we need to compute |<span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>j</i></sub></span> — <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"></sub>(<i>j</i> + 1)</span>|. Similarly to first step, we observe that only elements from <span class=\"tex-span\"><i>a</i></span> can appear on consecutive positions. We fix 2 indices i and j. We’re interested in how many permutations do <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> appear before <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i></sub></span>. We fix k such as on a permutation p, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> appears on position k and <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i></sub></span> appears on a position k + 1. In how many ways can we fix this? n – 1 ways (1, 2, …, n – 1). What’s left? A sequence of (n – 2) elements which can be permuted independently. So the sum of second step is |<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> - <i>a</i><sub class=\"lower-index\"><i>j</i></sub></span>| * (n – 1) * (n – 2)!, for each i != j. If I note (<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span> + <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span> + … + <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>) by S1 and |<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> - <i>a</i><sub class=\"lower-index\"><i>j</i></sub></span>| for each i != j by S2, the answer is (N – 1)! * S1 + (N – 1)! * S2 / N!. By a simplification, the answer is (S1 + S2) / N.</p><p>The only problem remained is how to calculate S2. Simple iteration won’t enter in time limit. Let’s think different. For each element, I need to make sum of differences between it and all smaller elements in the array a. As well, I need to make sum of all different between bigger elements than it and it. I’ll focus on the first part. I sort increasing array a. Suppose I’m at position <span class=\"tex-span\"><i>i</i></span>. I know that (i – 1) elements are smaller than <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. The difference is simply (i — 1) * <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> — sum_of_elements_before_position_i. Sum of elements before position i can be computed when iterating i. Let’s call the obtained sum Sleft. I need to calculate now sum of all differences between an element and bigger elements than it. This sum is equal to Sleft. As a proof, for an element <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, calculating the difference <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i></sub></span> — <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> when <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i></sub></span> > <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is equivalent to calculating differences between <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i></sub></span> and a smaller element of it (in this case <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>). That’s why Sleft = Sright.</p><p>As a conclusion, the answer is (S1 + 2 * Sleft) / N. For make fraction irreducible, you can use Euclid's algorithm. The complexity of the presented algorithm is <span class=\"tex-span\"><i>O</i>(<i>N</i> * <i>logN</i>)</span>, necessary due of sorting. Sorting can be implemented by count sort as well, having a complexity of O(maximalValue), but this is not necessary.</p><p>Official solution: <a href=\"/contest/340/submission/4383420\" title=\"Submission 4383420 by fchirica\">4383420</a></p><h2><a href=\"/contest/340/problem/D\" title=\"Codeforces Round 198 (Div. 2)\">340D - Bubble Sort Graph</a></h2><p>A good way to approach this problem is to notice that you can't build the graph. In worst case, the graph will be built in <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">2</sup>)</span> complexity, which will time out. Also, notice that "maximal independent set" is a NP-Hard task, so even if you can build the graph you can't continue from there. So, the correct route to start is to think of graph's properties instead of building it. After sketching a little on the paper, you should find this property:</p><p><strong>Lemma 1</strong> Suppose we choose 2 indices i and j, such as i < j. We'll have an edge on the graph between vertices <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i></sub></span> if and only if <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> > <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i></sub></span>. We'll call that i and j form an inversion in the permutation. </p><p><strong>Proof</strong> We assume we know the proof that bubble sort does sort correctly an array. To proof lemma 1, we need to show two things.</p> <ol> <li>Every inversion will be swapped by bubble sort.</li> <li>For each i < j when <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> < <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i></sub></span>, bubble sort will NOT swap this elements.</li> </ol><p>To proof 1, if bubble sort wouldn't swap an inversion, the sequence wouldn't be sorted. But we know that bubble sort always sorts a sequence, so all inversions will be swapped. Proofing 2 is trivial, just by looking at the code.</p><p>So far we've got how the graph G is constructed. Let's apply it in maximal independent set problem.</p><p><strong>Lemma 2</strong> A maximal independent set of graph G is a longest increasing sequence for permutation a. </p><p><strong>Proof</strong>: Suppose we have a set of indices <span class=\"tex-span\"><i>i</i>1</span> < <span class=\"tex-span\"><i>i</i>2</span> < ... <span class=\"tex-span\"><i>ik</i></span> such as <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i>1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i>2</sub></span>, ..., <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ik</i></sub></span> form an independent set. Then, anyhow we'd choose <span class=\"tex-span\"><i>d</i></span> and <span class=\"tex-span\"><i>e</i></span>, there won't exist an edge between <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>id</i></sub></span> and <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ie</i></sub></span>. According to proof 1, this only happens when <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>id</i></sub></span> < <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ie</i></sub></span>. Hence, an independent set will be equivalent to an increasing sequence of permutation a. The maximal independent set is simply the maximal increasing sequence of permutation a.</p><p>The task reduces to find longest increasing sequence for permutation <span class=\"tex-span\"><i>a</i></span>. This is a classical problem which can be solved in <span class=\"tex-span\"><i>O</i>(<i>N</i> * <i>logN</i>)</span>. <a href=\"//codeforces.com/blog/entry/8761\">Here</a> is an interesting discussion about how to do it. </p><h2><a href=\"/contest/340/problem/E\" title=\"Codeforces Round 198 (Div. 2)\">340E - Iahub and Permutations</a></h2><p>In this task, author's intended solution is an O(N ^ 2) dp. However, during testing <a class=\"rated-user user-orange\" href=\"/profile/Gerald\" title=\"Master Gerald\">Gerald</a> fount a solution using principle of inclusion and exclusion. We've thought to keep both solutions. We're sorry if you say the problem was well-known, but for both me and the author of the task, it was first time we saw it.</p><p><strong>Dynamic programming solution</strong></p><p>After reading the sequence, we can find which elements are deleted. Suppose we have in a set D all deleted elements. I'll define from now on a "free position" a position which has -1 value, so it needs to be completed with a deleted element. </p><p>We observe that some elements from D can appear on all free positions of permutation without creating a fixed point. The other elements from D can appear in all free positions except one, that will create the fixed point. It's intuitive that those two "classes" don't influence in the same way the result, so they need to be treated separated.</p><p>So from here we can get the dp state. Let dp(n, k) = in how many ways can I fill (n + k) free positions, such as n elements from D can be placed anywhere in the free position and the other k elements can be placed in all free positions except one, which will create the fixed point. As we'll prove by the recurrences, we are not interested of the values from elements of D. Instead, we'll interested in their property: if they can(not) appear in all free positions.</p><p>If k = 0, the problem becomes straight-forward. The answer for dp(n, 0) will be n!, as each permutation of (n + 0) = n numbers is valid, because all numbers can appear on all free positions. We can also calculate dp(n, 1). This means we are not allowed to place an element in a position out of (n + 1) free positions. However, we can place it in the other n positions. From now we get n elements which can be placed anywhere in the n free positions left. Hence, dp(n, 1) = n! * n.</p><p>We want to calculate dp(n, k) now, k > 1. Our goal is to reduce the number k, until find something we know how to calculate. That is, when k becomes 0 or 1 problem is solved. Otherwise, we want to reduce the problem to a problem when k becomes 0 or 1. I have two cases. In a first case, I take a number from numbers which can be placed anywhere in order to reduce the numbers which can form fixed points. In the second case, I take a number from those which can form fixed points in order to make the same goal as in the first case. Let's analyze them.</p><p>Case 1. Suppose X is the first free position, such as in the set of k numbers there exist one which cannot be placed there (because it will make a fixed point). Obviously, this position exist, otherwise k = 0. Also obviously, this position will need to be completed with a term when having a solution. In this case, I complete position X with one of n numbers. This will make number equal to X from the k numbers set to become a number which can be placed anywhere. So I "loose" one number which can be placed anywhere, but I also "gain" one. As well, I loose one number which can form a fixed point.</p><p>Hence dp(n, k) += n * dp(n, k — 1).</p><p>Case 2. In this case position X will be completed with one number from the k numbers set. All numbers which can form fixed points can appear there, except number having value equal to X. So there are k — 1 of them. I choose an arbitrary number Y from those k — 1 to place on the position X. This time I "loose" two numbers which could form fixed points: X and Y. As well, I "gain" one number which can be placed anywhere: X.</p><p>Hence dp(n, k) += (k — 1) * dp(n + 1, k — 2).</p><p><strong>TL;DR</strong></p><p>dp[N][0]=N!</p><p>dp[N][1]=N*dp[N][0]</p><p>dp[N][K]=N*dp[N][K-1]+(K-1)*dp[N+1][K-2] for K>=2</p><p>This recurrences can be computed by classical dp or by memoization. I'll present <a class=\"rated-user user-red\" href=\"/profile/DamianS\" title=\"Grandmaster DamianS\">DamianS</a>'s source, which used memoization. As you can see, it's very short and easy to implement. <a href=\"http://pastie.org/8286348\">Link</a></p><p><strong>Inclusion and exclusion principle</strong></p><p>I'll present here an alternative to the dynamic programming solution. Let's calculate in <span class=\"tex-span\"><i>tot</i></span> the number of deleted numbers. Also, let's calculate in <span class=\"tex-span\"><i>fixed</i></span> the <strong>maximal number of fixed points a permutation can have</strong>. For calculate <span class=\"tex-span\"><i>fixed</i></span>, let's iterate with an index <span class=\"tex-span\"><i>i</i></span> each permutation position. We can have a fixed point on position <span class=\"tex-span\"><i>i</i></span> if element from position <span class=\"tex-span\"><i>i</i></span> was deleted (<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> = -1) and element i does not exist in sequence <span class=\"tex-span\"><i>a</i></span>. With other words, element <span class=\"tex-span\"><i>i</i></span> was deleted and now I want to add it back on position <span class=\"tex-span\"><i>i</i></span> to obtain maximal number of fixed points. </p><p>We iterate now an index <span class=\"tex-span\"><i>i</i></span> from <span class=\"tex-span\"><i>fixed</i></span> to <span class=\"tex-span\">0</span>. Let sol[i] = the number of possible permutations having <em>exactly</em> <span class=\"tex-span\"><i>i</i></span> fixed points. Obviously, sol[0] is the answer to our problem. Let's introduce a <a href=\"https://en.wikipedia.org/wiki/Combination\">combination</a> <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a4b0ae77c1b1e95e3cba7276cfb7fecdb99b4221.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> representing in how many ways I can choose k objects out of n. I have list of positions which can be transformed into fix points (they are <span class=\"tex-span\"><i>fixed</i></span> positions). I need to choose <span class=\"tex-span\"><i>i</i></span> of them. According to the above definition, I get sol[i] = <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4cbfc413bd52e416b1fb7c018581f2467cb5a712.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> . Next, I have to fill <span class=\"tex-span\"><i>tot</i> - <i>i</i></span> positions with remained elements. We'll consider for this moment valid each permutation of not used values. So, sol[i] = <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/37e8612bbe476531470cec72cae3f7df22b9b162.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> . Where is the problem to this formula?</p><p>The problem is that it's possible, when permuting (tot — i) remained elements to be added, one (or more) elements to form more (new) fixed points. But if somehow I can exclude (subtract) the wrong choices from sol[i], sol[i] will be calculated correctly. I iterate another index <span class=\"tex-span\"><i>j</i></span> from i + 1 to <span class=\"tex-span\"><i>fixed</i></span>. For each j, I'll calculate how many permutations I considered in sol[i] having <span class=\"tex-span\"><i>i</i></span> fixed points but actually they have <span class=\"tex-span\"><i>j</i></span>. I'll subtract from sol[i] this value calculated for each j. If I do this, obviously sol[i] will be calculated correctly.</p><p>Suppose we fixed a j. We know that exactly sol[j] permutations have j fixed points (as j > i, this value is calculated correctly). Suppose now I fix a permutation having j fixed points. For get the full result, I need to calculate for all sol[j] permutations. Happily, I can multiply result obtained for a single permutation with sol[j] and obtain the result for all permutations having j fixed points. So you have a permutation having j fixed points. The problem reduces to choosing i objects from a total of j. Why? Those i objects chosen are actually the positions considered in sol[i] to be ones having exactly i fixed points. But permutation has j fixed points. Quoting for above, "For each j, I'll calculate how many permutations I considered in sol[i] having <span class=\"tex-span\"><i>i</i></span> fixed points but actually they have <span class=\"tex-span\"><i>j</i></span>" . This is exactly what algorithm does. </p><p>To sum up in a "LaTeX" way, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c44c16c69547f33183270573042717c9036b496b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>We can compute binomial coefficients using Pascal's triangle. Using inclusion and exclusion principle, we get <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">2</sup>)</span>. Please note that there exist an <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span> solution for this task, using inclusion and exclusion principle, but it's not necessary to get AC. I'll upload <a class=\"rated-user user-orange\" href=\"/profile/Gerald\" title=\"Master Gerald\">Gerald</a>'s source <a href=\"http://pastie.org/8287332\">here</a>.</p><h2><a href=\"/contest/341/problem/D\" title=\"Codeforces Round 198 (Div. 1)\">341D - Iahub and Xors</a></h2><p>The motivation of the problem is that x ^ x = 0. x ^ x ^ x… ^ x (even times) = 0</p><p><strong>Update per range, query per element</strong></p><p>When dealing with complicated problems, it's sometimes a good idea to try solving easier versions of them. Suppose you can query only one element each time (x0 = x1, y0 = y1). </p><p>To update a submatrix (x0, y0, x1, y1), I’ll do following operations. A[x0][y0] ^= val. A[x0][y1 + 1] ^= val. A[x1 + 1][y0] ^= val. A[x1 + 1][y1 + 1] ^= val.</p><p>To query about an element (X, Y), that element’s value will be the xor sum of submatrix A(1, 1, X, Y). Let’s take an example. I have a 6x6 matrix and I want to xor all elements from submatrix (2, 2, 3, 4) with a value. The below image should be explanatory how the method works:</p><p><img alt=\" \" src=\"https://imageshack.us/a/img96/8041/v83.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Next, by (1, 1, X, Y) I’ll denote xor sum for this submatrix.</p><p>“White” cells are not influenced by (2, 2, 3, 4) matrix, as matrix (1, 1, X, Y) with (X, Y) a white cell will never intersect it. “Red” cells are from the submatrix, the ones that need to be xor-ed. Note that for a red cell, (1, 1, X, Y) will contain the value we need to xor (as it will contain (2, 2)). Next, “blue” cells. For this ones (1, 1, X, Y) will contain the value we xor with, despite they shouldn’t have it. This is why both (2, 5) and (4, 2) will be xor-ed again by that value, to cancel the xor of (2, 2). Now it’s okay, every “blue” cell do not contain the xor value in their (1, 1, X, Y). Finally, the “green” cells. These ones are intersection between the 2 blue rectangles. This means, in their (1, 1, X, Y) the value we xor with appears 3 times (this means it is contained 1 time). For cancel this, we xor (4, 5) with the value. Now for every green cell (1, 1, X, Y) contains 4 equal values, which cancel each other.</p><p>You need a data structure do to the following 2 operations:</p> <ul> <li>Update an element (X, Y) (xor it with a value).</li> <li>Query about xor sum of (1, 1, X, Y).</li> </ul><p>Both operations can be supported by a Fenwick tree 2D. If you don't know this data structure, learn it and come back to this problem after you do this. </p><p><strong>Coming back to our problem</strong></p><p>Now, instead of finding an element, I want xor sum of a submatrix. You can note that xor sum of (x0, y0, x1, y1) is (1, 1, x1, y1) ^ (1, 1, x0 – 1, y1) ^ (1, 1, x1, y0 – 1) ^ (1, 1, x0 – 1, y0 – 1). This is a classical problem, the answer is (1, 1, x1, y1) from which I exclude what is not in the matrix: (1, 1, x0 – 1, y1) and (1, 1, x1, y0 – 1). Right now I excluded (1, 1, x0 – 1, y0 – 1) 2 times, so I need to add it one more time.</p><p>How to get the xor sum of submatrix (1, 1, X, Y)? In brute force approach, I’d take all elements (x, y) with 1 <= x <= X and 1 <= y <= Y and xor their values. Recall the definition of the previous problem, each element (x, y) is the xor sum of A(1, 1, x, y). So the answer is xor sum of all xor sums of A(1, 1, x, y), with 1 <= x <= X and 1 <= y <= Y.</p><p>We can rewrite that long xor sum. A number A[x][y] appears in exactly (X – x + 1) * (Y – y + 1) terms of xor sum. If (X – x + 1) * (Y – y + 1) is odd, then the value A[x][y] should be xor-ed to the final result exactly once. If (X — x + 1) * (Y — y + 1) is even, it should be ignored.</p><p>Below, you'll find 4 pictures. They are matrixes with X lines and Y columns. Each picture represents a case: (X odd, Y odd) (X even, Y even) (X even Y odd) (X odd Y even). Can you observe a nice pattern? Elements colored represent those for which (X – x + 1) * (Y – y + 1) is odd.</p><p><img alt=\" \" src=\"/predownloaded/97/11/9711911f5dae94dbd609bd95607f8abb0d241bcc.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> <img alt=\" \" src=\"/predownloaded/54/33/5433c6e1e6e6ac6345e898ea8a048a03404d4c1e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> <img alt=\" \" src=\"/predownloaded/b0/c2/b0c20ac42080a8eaad5a5c3d94241e916c12a767.bmp\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> <img alt=\" \" src=\"/predownloaded/20/e7/20e7d0f259c8907fe2e028da948843face8e5e3a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Yep, that's right! There are 4 cases, diving the matrix into 4 disjoint areas. When having a query of form (1, 1, X, Y) you only need specific elements sharing same parity with X and Y. This method works in O(4 * logN * logN) for each operation and is the indented solution. We keep 4 Fenwick trees 2D. We made tests such as solutions having complexity greater than O(4 * logN * logN) per operation to fail.</p><p>Here is our official solution: <a href=\"/contest/341/submission/4383473\" title=\"Submission 4383473 by fchirica\">4383473</a></p><h2><a href=\"/contest/341/problem/E\" title=\"Codeforces Round 198 (Div. 1)\">341E - Candies Game</a></h2><p><strong>Key observation</strong> Suppose you have 3 boxes containing A, B, C candies (A, B, C all greater than 0). Then, there will be always possible to empty one of boxes using some moves.</p><p><strong>Proof</strong> We can suppose that A <= B <= C. We need some moves such as the minimum from A, B, C will be zero. If we always keep the numbers in order A <= B <= C, it’s enough some moves such as A = 0. I’ll call this notation (A, B, C).</p><p>How can we prove that always exist such moves? We can use reductio ad absurdum to prove it. Let’s suppose, starting from (A, B, C) we can go to a state (A2, B2, C2). We suppose A2 (A2 > 0) is minimal from every state we can obtain. Since A2 is minimal number of coins that can be obtained and A2 is not zero, the statement is equivalent with we can’t empty one chest from configuration (A, B, C). Then, we can prove that from (A2, B2, C2) we can go to a state (A3, B3, C3), where A3 < A2. Obviously, this contradicts our assumption that A2 is minimal of every possible states. If A2 would be minimal, then there won’t be any series of moves to empty one chest. But A2 isn’t minimal, hence there always exist some moves to empty one chest.</p><p>Our algorithm so far:</p><p>void emptyOneBox(int A, int B, int C) {</p><p>if A is 0, then exit function.</p><p>Make some moves such as to find another state (A2, B2, C2) with A2 < A.</p><p>emptyOneBox (A2, B2, C2);</p><p>}</p><p>The only problem which needs to be proven now is: given a configuration (A, B, C) with A > 0, can we find another one (A2, B2, C2) such as A2 < A? The answer is always yes, below I’ll prove why.</p><p>Firstly, let’s imagine we want to constantly move candies into a box. It doesn't matter yet from where come the candies, what matters is candies arrive into the box. The box has initially X candies. After 1 move, it will have 2 * X candies. After 2 moves, it will have 2 * (2 * X) candies = 4 * X candies. Generally, after K moves, the box will contain 2^K * X candies.</p><p>We have A < B < C (if 2 numbers are equal, we can make a move and empty 1 box). If we divide B by A, we get from math that B = A * q + r. (obviously, always r < A). What if we can move exactly A * q candies from B to A? Then, our new state would be (r, B2, C2). We have now a number A2 = r, such as A2 < A.</p><p>How can we move exactly A * q coins? Let’s write q in base 2. Making that, q will be written as a sum of powers of 2. Suppose lim is the maximum number such as 2 ^ lim <= q. We get every number k from 0 to lim. For each k, I push into the first box (the box containing initially A candies) a certain number of candies. As proven before, I'll need to push (2 ^ k) * A candies. Let's take a look at the k-th bit from binary representation of q. If k-th bit is 1, B will be written as following: B = A * (2 ^ k + 2 ^ (other_power_1) + 2 ^ (other_power_2) + ...) + r. Hence, I'll be able to move A * (2 ^ k) candies from "B box" to "A box". Otherwise, I'll move from "C box" to "A box". It will be always possible to do this move, as C > B and I could do that move from B, too.</p><p>The proposed algorithm may look abstract, so let's take an example. </p><p>Suppose A = 3, B = 905 and C = 1024. Can we get less than 3 for this state?</p><p>B = 3 * 301 + 2. B = 3 * (100101101)2 + 2.</p><p>K = 0: we need to move (2^0) * 3 coins into A. 0th bit of q is 1, so we can move from B to A.</p><p>A = 6, B = 3 * (100101100)2 + 2 C = 1024</p><p>K = 1: we need to move (2 ^ 1) * 3 coins into A. Since 1th bit of q is already 0, we have to move from C.</p><p>A = 12, B = 3 * (100101100)2 + 2 C = 1018</p><p>K = 2: we need to move (2 ^ 2) * 3 coins into A. 2nd bit of q is 1, so we can move from B.</p><p>A = 24, B = 3 * (100101000)2 + 2 C = 1018</p><p>K = 3: we need to move (2 ^ 3) * 3 coins into A. 3nd bit of q is 1, so we can move from B.</p><p>A = 48, B = 3 * (100100000)2 + 2 C = 1018</p><p>K = 4. we need to move (2 ^ 4) * 3 coins into A. 4th bit of q is 0, we need to move from C.</p><p>A = 96, B = 3 * (100100000)2 + 2 C = 970</p><p>K = 5. we need to move (2 ^ 5) * 3 coins into A. 5th bit of q is 1, so we need to move from B.</p><p>A = 192, B = 3 * (100000000)2 + 2 C = 970</p><p>K = 6 we need to move (2 ^ 6) * 3 coins into A. We mve them from C.</p><p>A = 384 B = 3 * (100000000)2 + 2 C = 778</p><p>K = 7 we need to move (2 ^ 7) * 3 coins into A. We move them from C</p><p>A = 768 B = 3 * (100000000)2 + 2 C = 394</p><p>K=8 Finally, we can move our last 1 bit from B to A.</p><p>A = 1536 B = 3 * (000000000)2 + 2 C = 394</p><p>A = 1536 B = (3 * 0 + 2) C = 394</p><p>In the example, from (3, 905, 1024) we can arrive to (2, 394, 1536). Then, with same logic, we can go from (2, 394, 1536) to (0, X, Y), because 394 = 2 * 197 + 0.</p><p>This is how you could write emptyOneBox() procedure. The remained problem is straight-forward: if initially there are zero or one boxes having candies, the answer is "-1". Otherwise, until there are more than 2 boxes having candies, pick 3 boxes arbitrary and apply emptyOneBox(). </p><p>Here is a source implementing the algorithm. <a href=\"/contest/341/submission/4383485\" title=\"Submission 4383485 by fchirica\">4383485</a></p><h2>BONUS</h2><p>Instead of a conclusion, I'll post here related problems to the ones used in the round. :) Please note that some of them might be more easier / complicated than level of difficulty used in the round. Feel free to think of them / ask help / discuss them in the comment section :)</p><p><strong>Div2 A</strong> Suppose <span class=\"tex-span\"><i>x</i>, <i>y</i>, <i>A</i>, <i>B</i> ≤ 10<sup class=\"upper-index\">9</sup></span>. Instead of being asked how many bricks are colored with both red and pink in range <span class=\"tex-span\">[<i>A</i>, <i>B</i>]</span>, you're asked how many bricks are colored with at least one color. After you solve this one, solve the same problem, but instead of having 2 persons painting, you have k persons (<span class=\"tex-span\"><i>k</i> ≤ 20</span>). <a href=\"//codeforces.com/blog/entry/8755#comment-144971\">Solution</a> by <a class=\"rated-user user-violet\" href=\"/profile/Enchom\" title=\"Candidate Master Enchom\">Enchom</a></p><p><strong>Div2 B</strong> Given a very long list of special points, can you find quickly a convex special quadrilateral? Can you find very very quickly? :) Also, can you find maximal area of a special convex quadrilateral in time better than <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">4</sup>)</span>? Solutions for <a href=\"//codeforces.com/blog/entry/8755#comment-145790\">first problem</a> and <a href=\"//codeforces.com/blog/entry/8755#comment-145492\">second problem</a> provided by <a class=\"rated-user user-violet\" href=\"/profile/Xellos\" title=\"Candidate Master Xellos\">Xellos</a> and <a class=\"rated-user user-violet\" href=\"/profile/Enchom\" title=\"Candidate Master Enchom\">Enchom</a></p><p><strong>Div2 D / Div1 B</strong> Suppose the reverse problem. You are given a bubble sort graph having <span class=\"tex-span\"><i>N</i></span> vertices and <span class=\"tex-span\"><i>M</i></span> edges. Find its independent maximal set. Can you achieve <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">2</sup>)</span> to do this? Does a solution in <span class=\"tex-span\"><i>O</i>((<i>N</i> + <i>M</i>) + <i>N</i> * <i>logN</i>)</span> exist? <a href=\"//codeforces.com/blog/entry/8755#comment-144890\">Solution</a> by <a class=\"rated-user user-blue\" href=\"/profile/CountZero\" title=\"Expert CountZero\">CountZero</a></p><p><strong>Div2 E / Div1 C</strong> Find a solution running in liniar time. <a href=\"//codeforces.com/blog/entry/8755#comment-144888\">Solution (dynamic programming)</a> by <a class=\"rated-user user-violet\" href=\"/profile/ivan100sic\" title=\"Candidate Master ivan100sic\">ivan100sic</a> . <a href=\"//codeforces.com/blog/entry/8748#comment-144745\">Solution (inclusion exclusion principle)</a> by <a class=\"rated-user user-violet\" href=\"/profile/eduardische\" title=\"Candidate Master eduardische\">eduardische</a></p><p><strong>Div1 D</strong> Suppose the 3D version of this problem. You have a 3D matrix and you perform same QUERY/UPDATE operations, but using 6 parameters (a submatrix is defined now all elements a[i][j][k] for which x0 <= i <= x1, y0 <= j <= y1, z0 <= k <= z1). Can you get a solution using <span class=\"tex-span\"><i>O</i>(<i>log</i><sup class=\"upper-index\">3</sup> * <i>N</i>)</span> per query, having constant 8? But for d dimensions, does an <span class=\"tex-span\"><i>O</i>(2<sup class=\"upper-index\"><i>d</i></sup> * (<i>log</i><sup class=\"upper-index\"><i>d</i></sup>)<i>n</i>)</span> algorithm per query exist? :) <a href=\"//codeforces.com/blog/entry/8755#comment-144896\">Solution</a> by <a class=\"rated-user user-blue\" href=\"/profile/Dwylkz\" title=\"Expert Dwylkz\">Dwylkz</a>.</p><p><strong>Div1 E</strong> In our algorithm, we pick arbitrary 3 boxes. Can you find some heuristics of picking 3 boxes to reduce number of moves? </p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/340\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 198 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/341\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 198 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-12457-8810\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"12457\",\n blogEntryId: \"8755\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=198\" class=\"tag notice\" style=\"text-decoration: none;\">198</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8810\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+130</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8810\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/fchirica\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/fchirica\">\n fchirica\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Aug/30/2013 23:23\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8755#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8755#comments\">\n 82\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8826\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (77)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144799\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SeyedParsa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35492/avatar/21825d7789df0352.jpg'/> </a>\n <div><a href=\"/profile/SeyedParsa\" title=\"Master SeyedParsa\" class=\"rated-user user-orange\">SeyedParsa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/30/2013 23:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144799\" href=\"?#comment-144799\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144799\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144799\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-12\"\r\n data-commentUserId=\"35492\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-12</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144799\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great! Thanks for the detailed and accurate Editorial! <br /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144799 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144799 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144799\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144803\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Tparsa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/75633/avatar/f3c171fa286900c.jpg'/> </a>\n <div><a href=\"/profile/Tparsa\" title=\"Expert Tparsa\" class=\"rated-user user-blue\">Tparsa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/30/2013 23:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144803\" href=\"?#comment-144803\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144803\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"75633\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144803\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144803 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144803 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144803\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144811\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 01:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144811\" href=\"?#comment-144811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Lemma2 of 340 D is a little sudden for me. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144811\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144813\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ilyakor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/359/avatar/ac6a84569fcf8a43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/ilyakor\" title=\"Grandmaster ilyakor\" class=\"rated-user user-red\">ilyakor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 02:29\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144813\" href=\"?#comment-144813\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144813\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"20\"\r\n data-commentUserId=\"359\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+20</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144813\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Regarding problem D.</p> <blockquote><p>We made tests such as solutions having complexity greater than O(4 * logN * logN) per operation to fail.</p> </blockquote><p>Well, 4 * logN * logN (nit — O() notation here is incorrect, i.e. O(10000f) = O(f)) per operation also fails if it is not Fenwick tree (e.g., 2-d segment tree). Also, it seems that even carefully implemented Fenwick solution in Java runs longer than 0.5s, so TL should be >1s. Did jury have a Java solution?</p><p>I'd like also to note that for Fenwick trees there exists a more general approach for range updates, which works, e.g., for sum instead of xor (see <a href=\"http://petr-mitrichev.blogspot.ru/2013/05/fenwick-tree-range-updates.html\">this post</a>).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144813 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144813 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144813\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144824\" commentParentId=\"144813\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KADR\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1028/avatar/9089397f80c0fe42.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/KADR\" title=\"Master KADR\" class=\"rated-user user-orange\">KADR</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 08:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144824\" href=\"?#comment-144824\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144813\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144824\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"1028\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144824\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've got AC with 2-D segment tree.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144824 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144824 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144824\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144827\" commentParentId=\"144824\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/R_R_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/8865/avatar/dcf74f648e40d250.jpg'/> </a>\n <div><a href=\"/profile/R_R_\" title=\"International Master R_R_\" class=\"rated-user user-orange\">R_R_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 09:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144827\" href=\"?#comment-144827\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144824\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144827\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144827\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"8865\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144827\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Does your code have complexity O(logn*logn) for queries? I always thought that 2D segment tree is O(n) for queries like (1,1,1,n)</p><p><strong>Edit</strong>: Sorry, now I understand :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144827 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144827 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144827\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144828\" commentParentId=\"144827\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KADR\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1028/avatar/9089397f80c0fe42.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/KADR\" title=\"Master KADR\" class=\"rated-user user-orange\">KADR</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 09:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144828\" href=\"?#comment-144828\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144827\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144828\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"1028\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144828\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One should distinguish 2-D segment tree and quad-tree. The first one has complexity <span class=\"tex-span\"><i>O</i>(<i>logN</i>·<i>logN</i>)</span> per query, while the second one works in <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span> per query.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144828 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144828 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144828\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144878\" commentParentId=\"144828\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rubengt01\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/rubengt01\" title=\"Pupil rubengt01\" class=\"rated-user user-green\">rubengt01</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 00:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144878\" href=\"?#comment-144878\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144828\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144878\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"120886\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144878\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I implemented a quad tree and it was TLE in 6th test case. Can you help me to understand why an update or a query in a Quad tree is O(n). My solution stops the recursion when the interval asked or updated is same to the interval of the node. If you know an online explanation please share it. Thanks for the help <a href=\"//codeforces.com/contest/341/submission/4390134\">http://codeforces.com/contest/341/submission/4390134</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144878 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144878 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144878\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145175\" commentParentId=\"144878\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pushkarmishra\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/90420/avatar/e2f7bd3c3a048f5a.jpg'/> </a>\n <div><a href=\"/profile/pushkarmishra\" title=\"Specialist pushkarmishra\" class=\"rated-user user-cyan\">pushkarmishra</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/08/2013 03:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145175\" href=\"?#comment-145175\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144878\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145175\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"90420\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145175\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>try querying a 1xN row. you will realize that you ultimately have to query N 1-unit squares. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145175 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145175 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145175\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144835\" commentParentId=\"144813\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mugurelionut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63702/avatar/45e4d5390c215090.jpg'/> </a>\n <div><a href=\"/profile/mugurelionut\" title=\"International Master mugurelionut\" class=\"rated-user user-orange\">mugurelionut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 13:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144835\" href=\"?#comment-144835\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144813\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144835\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"63702\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144835\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Are you sure that the approach mentioned in Petr's post can be generalized to 2D or more dimensions (for supporting range updates and range queries) ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144835 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144835 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144835\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144924\" commentParentId=\"144835\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/02/2013 09:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144924\" href=\"?#comment-144924\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144835\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144924\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144924\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I suppose it can: <a href=\"//codeforces.com/contest/341/submission/4391440\">http://codeforces.com/contest/341/submission/4391440</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144924 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144924 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144924\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145437\" commentParentId=\"144924\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Igor_Kudryashov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/519/avatar/8c47a77b761709b6.jpg'/> </a>\n <div><a href=\"/profile/Igor_Kudryashov\" title=\"International Master Igor_Kudryashov\" class=\"rated-user user-orange\">Igor_Kudryashov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/12/2013 14:30\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145437\" href=\"?#comment-145437\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144924\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145437\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145437\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"519\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145437\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It is interesting) It is writen in statememnt that number <span class=\"tex-span\"><i>v</i></span> from update query <span class=\"tex-span\"> ≤ 2<sup class=\"upper-index\">62</sup></span>, but your solution using only int got accepted.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145437 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145437 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145437\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146133\" commentParentId=\"145437\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/R_R_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/8865/avatar/dcf74f648e40d250.jpg'/> </a>\n <div><a href=\"/profile/R_R_\" title=\"International Master R_R_\" class=\"rated-user user-orange\">R_R_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 12:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146133\" href=\"?#comment-146133\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145437\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146133\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"8865\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146133\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maybe it's because only the parity of the number matter, so overflow doesn't affect the result?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146133 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146133 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146133\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144818\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SuprDewd\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/15989/avatar/30d83ec6ea29a050.jpg'/> </a>\n <div><a href=\"/profile/SuprDewd\" title=\"Candidate Master SuprDewd\" class=\"rated-user user-violet\">SuprDewd</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 03:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144818\" href=\"?#comment-144818\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144818\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"36\"\r\n data-commentUserId=\"15989\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+36</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144818\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Realizing that the "Bubble Sort Graph" problem was equivalent to finding the length of the longest increasing subsequence was a really nice "Aha!" moment for me. Great problems, thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144818 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144818 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144818\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144836\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lxyxynt\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4130/avatar/77800d1adbf53169.jpg'/> </a>\n <div><a href=\"/profile/lxyxynt\" title=\"Candidate Master lxyxynt\" class=\"rated-user user-violet\">lxyxynt</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 13:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144836\" href=\"?#comment-144836\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144836\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"4130\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144836\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Where are the pictures in 341D?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144836 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144836 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144836\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144955\" commentParentId=\"144836\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 13:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144955\" href=\"?#comment-144955\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144836\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144955\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144955\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>They work perfectly for me. I uploaded them at imageshack.us . Maybe you a problem with that server. Please, tell me a server for which the images will be visible to you and I'll upload there.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144955 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144955 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144955\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144963\" commentParentId=\"144955\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lxyxynt\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4130/avatar/77800d1adbf53169.jpg'/> </a>\n <div><a href=\"/profile/lxyxynt\" title=\"Candidate Master lxyxynt\" class=\"rated-user user-violet\">lxyxynt</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 17:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144963\" href=\"?#comment-144963\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144955\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144963\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4130\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144963\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you for your kind reply! it's visible to me now.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144963 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144963 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144963\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144844\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kyuubi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83590/avatar/b87432a652bb276.jpg'/> </a>\n <div><a href=\"/profile/Kyuubi\" title=\"Expert Kyuubi\" class=\"rated-user user-blue\">Kyuubi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 14:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144844\" href=\"?#comment-144844\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144844\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"83590\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144844\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For 340B I used the Gift Wrap alogirithm to compute a Convex Hull for the points, and then using a DP found the minimum Area that needs to be cut off from this Hull to form a quadrilateral. </p><p>Worst Case for Hull O(n^3) + DP O(n^2) Total execution time was 30ms</p><p>The only corner case was when the hull is composed of only 3 points. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144844 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144844 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144844\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144848\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 16:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144848\" href=\"?#comment-144848\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144848\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144848\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I found that most of the solutions marked correct for the problem 340D gave the answer 1 for the input</p><p>3 12 13 1</p><p>Whereas it should have been 2(maximal set can be {12,13}). Did the test cases miss something or am I making a really silly mistake here?</p><p>Can I hack solutions after the match has ended. If so could anyone please let me know.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144848 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144848 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144848\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144851\" commentParentId=\"144848\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 16:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144851\" href=\"?#comment-144851\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144848\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144851\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144851\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My bad :(. I just re-read the problem and found that the numbers can be <=n</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144851 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144851 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144851\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144856\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/HekpoMaH\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62637/avatar/38b1193a84b213e9.jpg'/> </a>\n <div><a href=\"/profile/HekpoMaH\" title=\"Specialist HekpoMaH\" class=\"rated-user user-cyan\">HekpoMaH</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 19:04\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144856\" href=\"?#comment-144856\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144856\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"62637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144856\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"//codeforces.com/blog/entry/8761\">http://codeforces.com/blog/entry/8761</a> PLS help!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144856 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144856 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144856\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144863\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Azat_Yusupov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30140/avatar/a9bdb2076a46d716.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Azat_Yusupov\" title=\"Candidate Master Azat_Yusupov\" class=\"rated-user user-violet\">Azat_Yusupov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 19:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144863\" href=\"?#comment-144863\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144863\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"30140\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144863\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks to author for the contest. It was the best raund I have ever seen.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144863 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144863 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144863\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144868\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hashbash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/66704/avatar/92e9040cf5324c99.jpg'/> </a>\n <div><a href=\"/profile/hashbash\" title=\"Specialist hashbash\" class=\"rated-user user-cyan\">hashbash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 21:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144868\" href=\"?#comment-144868\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144868\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"66704\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144868\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you please elaborate on how the (i — 1) * ai = sum_of_elements_before_position_i in question 341C ???</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144868 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144868 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144868\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144958\" commentParentId=\"144868\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 15:50\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144958\" href=\"?#comment-144958\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144868\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144958\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144958\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For a fixed ai, you need to calculate sum of ai — aj, when aj < ai. If I sort sequence a in increasing order, then all elements aj < ai will be in positions {1, 2, ..., i — 1}. So I need to calculate ai — a1 + ai — a2 + ... ai — a(i-1). Ai appears (i — 1) times in this sum, so I re-write the sum being (i — 1) * ai — a1 — a2 — ... — a(i — 1). This is (i — 1) * ai — (a1 + a2 + ... + a(i — 1)). I need to sum for each i this expression. It can be computed in O(N), see my source for reference. There, sumBefore is (a1 + a2 + ... + a(i — 1)).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144958 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144958 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144958\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144959\" commentParentId=\"144958\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hashbash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/66704/avatar/92e9040cf5324c99.jpg'/> </a>\n <div><a href=\"/profile/hashbash\" title=\"Specialist hashbash\" class=\"rated-user user-cyan\">hashbash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 16:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144959\" href=\"?#comment-144959\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144958\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144959\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"66704\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144959\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for your reply.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144959 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144959 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144959\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144884\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/DieAnderen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/DieAnderen\" title=\"Specialist DieAnderen\" class=\"rated-user user-cyan\">DieAnderen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 01:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144884\" href=\"?#comment-144884\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144884\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"16\"\r\n data-commentUserId=\"106427\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+16</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144884\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try Geogebra to draw good Geometric figures. It's free.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144884 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144884 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144884\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144886\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/karan173\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/karan173\" title=\"Expert karan173\" class=\"rated-user user-blue\">karan173</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 02:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144886\" href=\"?#comment-144886\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144886\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53106\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144886\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For 340E, can't we just do dp[n][k] = n*dp[n-1][k] + k*dp[n][k-1] ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144886 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144886 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144886\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144887\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 05:05\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144887\" href=\"?#comment-144887\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144887\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144887\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>This is the most explanatory editorial I have ever seen on codeforces :) Really nice work guys :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144887 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144887 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144887\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144888\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ivan100sic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/26422/avatar/611ce74705dadb74.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/ivan100sic\" title=\"International Grandmaster ivan100sic\" class=\"rated-user user-red\">ivan100sic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 07:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144888\" href=\"?#comment-144888\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144888\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"26422\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144888\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well, turns out div2 E / div1 C has an even simpler O(N) solution. Take a look at <a class=\"rated-user user-blue\" href=\"/profile/problem-solved\" title=\"Expert problem-solved\">problem-solved</a>'s elegant <a href=\"//codeforces.com/contest/341/submission/4384292\">solution</a>, or perhaps <a href=\"//codeforces.com/contest/341/submission/4377177\">mine</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144888 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144888 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144888\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144892\" commentParentId=\"144888\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Solitary\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Solitary\" title=\"Expert Solitary\" class=\"rated-user user-blue\">Solitary</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 10:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144892\" href=\"?#comment-144892\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144888\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144892\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"126956\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144892\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just like the number of desarrangements of length n,right?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144892 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144892 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144892\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144900\" commentParentId=\"144888\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/karan173\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/karan173\" title=\"Expert karan173\" class=\"rated-user user-blue\">karan173</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 15:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144900\" href=\"?#comment-144900\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144888\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144900\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53106\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144900\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>please explain the solution.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144900 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144900 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144900\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145055\" commentParentId=\"144888\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/accidentallygivenfuck\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34459/avatar/c4e2278aa2ac1176.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/accidentallygivenfuck\" title=\"Expert accidentallygivenfuck\" class=\"rated-user user-blue\">accidentallygivenfuck</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/07/2013 10:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145055\" href=\"?#comment-145055\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144888\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145055\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34459\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145055\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you please tell, what <code>+(i-1)*D[i-2]</code> is needed for?<br />I had an idea like this (which got WA, I still dont know why). Here: </p> <pre><code>D[i] = ends*D[i-1] + (i-1)*D[i-1];\nD[i] = (ends+i-1)*D[i-1];\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145055 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145055 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145055\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145057\" commentParentId=\"145055\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/accidentallygivenfuck\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34459/avatar/c4e2278aa2ac1176.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/accidentallygivenfuck\" title=\"Expert accidentallygivenfuck\" class=\"rated-user user-blue\">accidentallygivenfuck</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/07/2013 10:41\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145057\" href=\"?#comment-145057\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145055\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145057\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145057\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34459\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145057\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>BTW, my idea is:<br />I place <span class=\"tex-span\"><i>i</i></span> in <span class=\"tex-span\"><i>i</i><sup class=\"upper-index\"><i>th</i></sup></span> position (which makes fixed point). Then for each <span class=\"tex-span\"><i>D</i>[<i>i</i> - 1]</span> permutations, I swap <span class=\"tex-span\"><i>i</i></span> with some other number, as none of the rest will make fixed point while in <span class=\"tex-span\"><i>i</i><sup class=\"upper-index\"><i>th</i></sup></span> position, and <span class=\"tex-span\"><i>i</i></span> won't make fixed point in any other position. So for each <span class=\"tex-span\"><i>D</i>[<i>i</i> - 1]</span> (correct) permutations, I have <span class=\"tex-span\">(<i>ends</i> + <i>i</i> - 1)</span> different numbers to swap <span class=\"tex-span\"><i>i</i></span> with and I get <code>D[i] = (ends+i-1)*D[i-1]</code>. But I miss something, something with <code>D[i-2]</code>. :(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145057 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145057 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145057\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144890\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 09:05\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144890\" href=\"?#comment-144890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div2 D Bonus <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> solution. If there is no edge between vertices <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> > <i>a</i><sub class=\"lower-index\"><i>j</i></sub></span>, then <span class=\"tex-span\"><i>i</i> > <i>j</i></span>, else <span class=\"tex-span\"><i>i</i> < <i>j</i></span>. One is easy to build the original sequence by applying any sorting algorithm with this comparator</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144890\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144975\" commentParentId=\"144890\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/04/2013 01:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144975\" href=\"?#comment-144975\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144890\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144975\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144975\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice solution. :) I didn't thought of that one. BTWs, for those interested there exist one way to build the sequence in linear time. You can google about research article: McConnell, Ross M.; Spinrad, Jeremy P. (1999), "Modular decomposition and transitive orientation"</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144975 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144975 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144975\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144896\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dwylkz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30502/avatar/462a9dcaf9fca2c4.jpg'/> </a>\n <div><a href=\"/profile/Dwylkz\" title=\"Specialist Dwylkz\" class=\"rated-user user-cyan\">Dwylkz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 12:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144896\" href=\"?#comment-144896\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144896\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144896\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"30502\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144896\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here is my solution for 341D.</p><p><strong>Define</strong>: "sum" stand for <span class=\"tex-span\"><i>xor</i></span> sum. <span class=\"tex-span\"> + , - </span> stand for <span class=\"tex-span\"><i>xor</i></span>. <span class=\"tex-span\"><i>a</i> * <i>b</i></span> means that apply <span class=\"tex-span\"><i>b</i> + <i>b</i></span> for <span class=\"tex-span\"><i>a</i> - 1</span> times.</p> <ol> <li><p>Notice that we could do <span class=\"tex-span\"> + </span> and <span class=\"tex-span\"> - </span> subtraction interval-wise.</p></li> <li><p>But Fenwick tree could only update per range and query per element or vice versa.</p></li> <li><p>If, for each element, say, <span class=\"tex-span\"><i>ft</i>(<i>x</i>, <i>y</i>)</span> hold the sum of prefix sum of the matrix <span class=\"tex-span\">(1, 1, <i>x</i>, <i>y</i>)</span> (ie. prefix sum of prefix sum of <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span>), then for each query, <span class=\"tex-span\"><i>ft</i>(<i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>) - <i>ft</i>(<i>x</i><sub class=\"lower-index\">0</sub> - 1, <i>y</i><sub class=\"lower-index\">1</sub>) - <i>ft</i>(<i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">0</sub> - 1) + <i>ft</i>(<i>x</i><sub class=\"lower-index\">0</sub> - 1, <i>y</i><sub class=\"lower-index\">0</sub> - 1)</span> would be the result. As the difference between prefix-sum is the sum of the corresponding interval.</p></li> <li><p>And it's easy to <span class=\"tex-span\"><i>xor</i></span> a <span class=\"tex-span\"><i>v</i></span> to elements in submatrix <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">0</sub>, <i>y</i><sub class=\"lower-index\">0</sub>, <i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>)</span>.</p></li> <li><p>Consider 1 dimension version of this problem. For a sequence <span class=\"tex-span\"><i>a</i></span>, the prefix sum of <span class=\"tex-span\"><i>x</i></span> is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0c328f79f88844c99902ced4f17316c1518417a8.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and the prefix sum of prefix sum of x is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/310eecfbb820cd40a1a8bd63ccbbd3f9119d208f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p></li> <li><p>Hence, all we have to do is to maintain an extra sequnce <span class=\"tex-span\"><i>i</i> * <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p></li> <li><p>Then expand method above to arbitrary dimension.</p></li> </ol><p>Here is an <a href=\"//codeforces.com/contest/341/submission/4391987\">implement</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144896 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144896 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144896\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145260\" commentParentId=\"144896\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pushkarmishra\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/90420/avatar/e2f7bd3c3a048f5a.jpg'/> </a>\n <div><a href=\"/profile/pushkarmishra\" title=\"Specialist pushkarmishra\" class=\"rated-user user-cyan\">pushkarmishra</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/09/2013 16:20\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145260\" href=\"?#comment-145260\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144896\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145260\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145260\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"90420\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145260\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can your method also be used if we have to perform the following operations on a 2D matrix:</p> <ol> <li>update x1, y1, x2, y2, k. in this operation, we add k to each element in sub-matrix x1, y1, x2, y2.</li> <li>query x1, y1, x2, y2. in this, we output the sum of all elements in sub-matrix x1, y1, x2, y2.</li> </ol><p>can the same logic be extended??</p><p>EDIT: Yes, it can be. thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145260 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145260 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145260\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145295\" commentParentId=\"145260\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dwylkz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30502/avatar/462a9dcaf9fca2c4.jpg'/> </a>\n <div><a href=\"/profile/Dwylkz\" title=\"Specialist Dwylkz\" class=\"rated-user user-cyan\">Dwylkz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/10/2013 05:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145295\" href=\"?#comment-145295\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145260\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145295\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145295\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30502\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145295\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes, and, it could be extended to 3 or more dimensions, too :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145295 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145295 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145295\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144899\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 15:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144899\" href=\"?#comment-144899\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144899\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144899\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nicely written tutorial, and really good round in my opinion, looking forward for the solution of problem 341E, and also loving the idea of Bonus problems, really good authors! Thank you for the lovely round! :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144899 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144899 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144899\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144902\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TsunamiNoLetGo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63066/avatar/2e9b4d0dfeda8d47.jpg'/> </a>\n <div><a href=\"/profile/TsunamiNoLetGo\" title=\"Master TsunamiNoLetGo\" class=\"rated-user user-orange\">TsunamiNoLetGo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 17:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144902\" href=\"?#comment-144902\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144902\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"63066\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144902\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>340-B maximum area quad is really tough to pass the time limit with python ! I can see no accepted solutions !!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144902 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144902 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144902\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144953\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/alibaba\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/alibaba\" title=\"Expert alibaba\" class=\"rated-user user-blue\">alibaba</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 12:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144953\" href=\"?#comment-144953\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144953\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144953\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"97169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144953\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem Div2 340E , in the case 2 : "Case 2. In this case position X will be completed with one number from the k numbers set..." if the position X with X is an used number, how the total number of elements which can be placed anywhere increase? For example n = 7 , -1 -1 4 2 -1 -1 -1 => N = 1 {3 } , K = 4 {1 , 5, 6, 7} , so if we put a number in K at position 2, the number of N will not increased!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144953 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144953 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144953\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144954\" commentParentId=\"144953\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 13:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144954\" href=\"?#comment-144954\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144953\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144954\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144954\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>X positions can be {1, 5, 6, 7}. Only those positions can create fixed points. Suppose we choose now arbitrary X = 1. I can place there numbers Y = {5, 6, 7}. Now, permutation will look like Y -1 4 2 -1 -1 -1. Obviously, 1 can be placed anywhere now, hence number N is increased.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144954 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144954 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144954\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144956\" commentParentId=\"144954\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/alibaba\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/alibaba\" title=\"Expert alibaba\" class=\"rated-user user-blue\">alibaba</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 15:22\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144956\" href=\"?#comment-144956\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144954\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144956\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"97169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144956\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you for your answer, but I am still not clear :D</p><p>About position number 2, which case it corresponding to? like in the above case -1 Y 4 2 -1 -1 -1 -> number N will not increased.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144956 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144956 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144956\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144957\" commentParentId=\"144956\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 15:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144957\" href=\"?#comment-144957\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144956\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144957\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144957\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144957\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You don't deal with it for the moment. You deal only with set of positions {1, 5, 6, 7}. Each time, you reduce one or two elements from the set (depending of choosing case 1 or case 2). When set has 0 or 1 element, then you can handle the other positions (see initialization of dp, it will handle position 2 also). As each time K decreases by 1 or 2, it's obvious sometime you'll be in the basic case, when you'll handle the other positions. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144957 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144957 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144957\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144961\" commentParentId=\"144957\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/alibaba\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/alibaba\" title=\"Expert alibaba\" class=\"rated-user user-blue\">alibaba</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 17:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144961\" href=\"?#comment-144961\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144957\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144961\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"97169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144961\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you :D will need time to digest it. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144961 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144961 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144961\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144971\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 23:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144971\" href=\"?#comment-144971\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144971\" revisionCount=\"9\" revision=\"9\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">9</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144971\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144971\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder if the authors will post the solutions to bonus problems after some time? :)</p><p>Anyway, here is my idea of the Div2 A — Bonus, sorry if there is much simpler solution, this is what i thought of :)</p><p>Let's say that the i-th painter will paint all bricks divisible by X[i]. I will assume that the least common multiple of X[1], X[2], X[3]...X[k] will fit in long long. (If it doesn't you can easily still solve it using the same method, it's just for the sake of simplicity). Let's define a certain colouring by a binary number. The <strong>1</strong>s in the binary number correspond to the colors that were surely used ( <strong>0</strong> doesn't necessary mean the colour isn't used ). For example for K=5, 10100 would define that surely the first and third colours were used in that colouring.</p><p>To get the answer we iterate over all possible colourings, and if the colouring contains odd number of ones, we add the amount of bricks that are coloured that way, otherwise we remove that amount. The solution has complexity O(2^k*log) if implemented good, because there are 2^k possible colourings and for each we need to find the least common multiple of the used colours to determine the amount of bricks that are coloured that way.</p><p>I know it sounds quite weird and at the moment i'm struggling to find a proof, but i have tested it and it works. If someone could provide a proof that would be great :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144971 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144971 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144971\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144972\" commentParentId=\"144971\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/04/2013 00:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144972\" href=\"?#comment-144972\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144971\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144972\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144972\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, I'll post my ideas for Bonus tasks if there are enough persons interested. :) This is a classic task solvable by inclusion and exclusion principle. If I understood well what your solution does, it uses exactly this principle. Google it and you'll find proof for your solution :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144972 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144972 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144972\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144974\" commentParentId=\"144972\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/04/2013 00:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144974\" href=\"?#comment-144974\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144972\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144974\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144974\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144974\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'd love to see the solutions, i've spent A LOT of time on those bonus problems :).</p><p>Here is what i consider to be my "proof" for the solution i described above :P</p><p><strong>Proof</strong></p><p>Let's imagine we are iterating the binary numbers in order of increasing amount of ones in them. If we are for example at the number 01010, then we want to count the bricks colored that way, exactly once. However we have already counted them when looking at binary numbers 01000 and 00010. So how many times exactly have we counted a given binary number? Well if the binary number has exactly P ones in it, then we have counted it C(1,P) times when looking at numbers with 1 one in them, C(2,P) times when looking at numbers with 2 ones in them and so on. However remember that we do not always add, we subtract too, so we get the following :</p><p>For a number with P ones in it, we have counted it exactly S times where <strong>S=C(1,P)-C(2,P)+C(3,P)-C(4,P)+C(5,P)...C(P-1,P).</strong></p><p>Well it took me quite a lot of time, but not that difficultly it can be proven that <strong>-C(0,P)+C(1,P)-C(2,P)+C(3,P)...C(P,P) equals 0</strong>, therefor obviously for odd P, S=0 and for even P — S=2. And since we want to count each colouring exactly ones, obviously for odd P, we add it once and for even P we subtract it.</p><p>C(K,N) = <a href=\"https://en.wikipedia.org/wiki/Binomial_coefficient\">binomial coefficient</a></p><p>It's a little bit clumsy but i made it myself because i haven't heard about inclusion-exclusion principle :)</p><p>P.S. Sorry for all those long posts, i just really liked the problems and spent a lot of time on them :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144974 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144974 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144974\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144973\" commentParentId=\"144971\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sparik\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83327/avatar/226632cbc2cf9c5.jpg'/> </a>\n <div><a href=\"/profile/sparik\" title=\"Candidate Master sparik\" class=\"rated-user user-violet\">sparik</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/04/2013 00:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144973\" href=\"?#comment-144973\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144971\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144973\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"83327\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144973\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think this is the simplest solution. It uses inclusion-exclusion principle. <a href=\"http://www.spoj.com/problems/NGM2/\">This problem on SPOJ</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144973 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144973 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144973\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145248\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akshayk0406\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/akshayk0406\" title=\"Pupil akshayk0406\" class=\"rated-user user-green\">akshayk0406</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/09/2013 14:05\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145248\" href=\"?#comment-145248\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145248\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4596\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145248\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem 340C</p><p>I didn't understand second step to calculate sum_of_all_routes. Can someone explain with the help of example.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145248 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145248 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145248\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145285\" commentParentId=\"145248\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Cer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Cer\" title=\"Specialist Cer\" class=\"rated-user user-cyan\">Cer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/09/2013 21:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145285\" href=\"?#comment-145285\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145248\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145285\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145285\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"119611\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145285\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>this step is to compute the sum of all possible differences |ai-aj| where (i != j) in all possible permutations.</p><p>consider we have the sequence a1, a2, a3, a4, a5, a6 and we want to get how many times a2 will come before a3 directly by keeping a1 a4 a5 a6 in this order as a subsequence I will list all those permutations that fullfill the last condition : a2 a3 a1 a4 a5 a6</p><p>a1 a2 a3 a4 a5 a6</p><p>a1 a4 a2 a3 a5 a6</p><p>a1 a4 a5 a2 a3 a6</p><p>a1 a4 a5 a6 a2 a3</p><p>and the number of those permutations is n-1 = 6-1 = 5. and those 5 times is when a1 a4 a5 a6 comes in this order and to compute how many times for all possible orders of a1 a4 a5 a6 then we multiply by (n-2)! = (6-2)! = 4! = 24 so the number of times that a2 a3 comes consecutivly is (n-1)*(n-2)! = (n-1)! and the sum of all differences |a2-a3| is (n-1)!*|a2-a3|. S2 is the sum of all differences |ai - aj| for each i != j .</p><p>to compute S2 : for each ai we want to compute the differece between it and all other elements aj where i != j and let us sort the given sequence a1 a2 a3 a4 a5 a6 in increasing order then the sum of all differences |ai — ak| where k<i is (i-1)*ai — (sum_of_elements_before_position_i) lets call this sum is slefti then we find slefti for each i and let sleft = sleft1 + sleft2 + sleft3 ..... + sleft6 = sum_of(slefti) for i= 1 to n when we compute sleft we find that sright = sleft where sright = sright1 + sright2 + .... + sright6 and we know that S2 = sleft + sright = 2*sleft </p><p>so the last result will be (S1 + S2) / n = (S1 + 2*sleft) / n and to make the fraction in simplest form we divide both of (S1+S2) and n on GCD((s1+s2),n)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145285 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145285 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145285\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145298\" commentParentId=\"145285\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akshayk0406\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/akshayk0406\" title=\"Pupil akshayk0406\" class=\"rated-user user-green\">akshayk0406</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/10/2013 09:05\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145298\" href=\"?#comment-145298\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145285\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145298\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4596\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145298\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks, that was very good explaination. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145298 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145298 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145298\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146123\" commentParentId=\"145285\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lucaspala\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lucaspala\" title=\"Newbie lucaspala\" class=\"rated-user user-gray\">lucaspala</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 08:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146123\" href=\"?#comment-146123\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145285\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146123\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"119656\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146123\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why they are dividing s2 * (n-1)! to n!? Please help me</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146123 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146123 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146123\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145492\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 01:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145492\" href=\"?#comment-145492\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145492\" revisionCount=\"6\" revision=\"6\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">6</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145492\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"15\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145492\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here is my idea on the Div2 B "Can you find maximal area convex quadrilateral", I spent a lot of time on it because it was the only problem that the author didn't have solution for :).</p><p>Its only theoretical, I haven't tested it because I am not able to write source now (I'm currently at the Balkan Olympiad), so if it is wrong please do not hate :)</p><p><strong>My solution</strong></p><p>Ok first, we need to find a way to check if a quadrilateral is convex while constructing it, and to do that we can simply use that quadrilateral's diagonals cross if and only if it's convex. Therefor if we find two crossing lines, created from 4 special points, we have a special convex quadrilateral.</p><p>Now as first step of our algorithm, we will take every two points and construct a line, let the points be A and B, then we will imagine its infinite continuation in the plane, and also two infinite lines perpendicular to our line and crossing it in the special points. That will divide the plane in 6 sections, but for the sake of simplicity we will look only on 3 of them (on one of the sides) because they are simetrical. Here is a picture (special points are red) :</p><p><img alt=\" \" src=\"/predownloaded/04/b2/04b22291765bdf15839e99944b5cddf8f1a31779.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>So we have three zones, blue, green and yellow. Now let's look at all other special points that are in one of those zones. We will do a few rotating sweeping lines to have some ordered sets of points. First sweeping line will start from point A to infinite in direction opposite to B paralel to AB and save all the points in the <strong>BLUE AREA ONLY</strong> , second line will start from point A to infinite being perpendicular to AB and will save all points in the <strong>GREEN AREA ONLY</strong>, third line is the same as the second but starts from B and rotates in the opposite direction, again saves all points in the <strong>GREEN AREA ONLY</strong>, and fourth and last line is same as the first, but start from B and saves all points in the <strong>YELLOW AREA ONLY</strong>. Here is a picture of the lines and their rotating directions :</p><p><img alt=\" \" src=\"/predownloaded/90/a1/90a16ea1ffdaec788c2b32e2c5c7fcb63738809b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>For each special point we will save the cross product it gives with line AB. So for each line we have four sets of points where the second and third actually contain the same points but with different orderings. We put those 4 sets in 4 RMQ structures so we could later get the highest of the cross products in some interval fast. Assuming we use roughly O(N*LOGN) for the sweeping lines and to build RMQ, and O(N^2) to fix a line, we have complexity of O(N^3*LOGN) for now.</p><p>Now let's proceed with our actual solution. We fix a line AB and a third point C. Now we want such point D so that AB and CD cross (being the diagonals of convex quadrilateral) and the cross product of D to the line AB is maximum. Let's look at a picture of points A,B and C :</p><p><img alt=\" \" src=\"/predownloaded/11/e9/11e9e5f8f9e2a5ad97396fb10016de0db20efdad.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Obviously for CD to cross AB, D must be in the area marked with white above. So now how to fast get the point with maximum cross product to AB in that white area? Well we have 3 different cases depending on the place of C in the initial 6 zones that I divided the plane into. Let's take a look.</p><p><strong>Case 1</strong></p><p>When C is on the other side of the <strong>blue area</strong></p><p><img alt=\" \" src=\"/predownloaded/8d/e1/8de155f6e990f50da4bd43c1d85ab26eca1c08e2.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>So obviously we want D to be in the pink area, pink area covers part of the green and part of the yellow areas. For the green area we can use the set of points from sweeping line 2. By binary we will find the first point that is in the pink area, and then get RMQ query for that suffix of the array of points. Same thing we can do with the yellow area, using the points from sweeping line 4. Therefor we can find the best point D in O(LOGN).</p><p><strong>Case 2</strong></p><p>When C is on the other side of the <strong>green area</strong></p><p><img alt=\" \" src=\"/predownloaded/09/73/09733f3479756bb9177f87b4ac6a78b0baa06449.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Now obviously we cover the whole green area, so we can just call a RMQ query of the whole range on any of the sweeping line 2 or 3, and for the blue part that is covered, we can again do binary and then RMQ query in points from sweep line 1, and the same thing for the yellow parts, with the points from sweep line 4.</p><p><strong>Case 3</strong></p><p>When C is on the other side of the <strong>yellow area</strong></p><p>I'm not gonna show a picture of that as it is really symmetrical to case 1, you just again use binary and RMQ query in sweep lines 1 and 3 for the blue and green parts that are covered.</p><p>Obviously each test case takes roughly O(LOGN) and fixing points A,B,C is O(N^3), so i think that solution would be O(N^3*LOGN) in general. I'm sorry if it is wrong i am unable to test it right now, but I really took a lot of time to explain it nicely (sorry if it isn't very understandable), so hope I helped :)</p><p>P.S. Sorry for the long post, I was excited to share my idea :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145492 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145492 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145492\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145493\" commentParentId=\"145492\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sweiss\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/sweiss\" title=\"Grandmaster sweiss\" class=\"rated-user user-red\">sweiss</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 01:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145493\" href=\"?#comment-145493\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145492\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145493\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"412\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145493\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>dude, you're awesome!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145493 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145493 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145493\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145496\" commentParentId=\"145492\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 01:44\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145496\" href=\"?#comment-145496\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145492\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145496\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145496\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Isn't the author's solution <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">3</sup>)</span>?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145496 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145496 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145496\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145497\" commentParentId=\"145496\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 01:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145497\" href=\"?#comment-145497\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145496\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145497\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145497\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145497\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Author's solution describes a solution for finding maximal area quadrilateral, however it doesn't guarantee it will be a convex one. In the bonus tasks the author asked if anyone could find a maximal area <strong>convex</strong> quadrilateral in less than O(N^4), because he couldn't find a solution, and I took it as a challenge. It is a bonus task :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145497 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145497 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145497\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145498\" commentParentId=\"145497\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 02:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145498\" href=\"?#comment-145498\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145497\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145498\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145498\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah, right. I didn't notice that. Seems quite tough to implement... well done.</p><p>And a challenge atop a challenge: yesterday's gym ACM training, problem I: find the largest convex <strong>polygon</strong> which doesn't contain any of additional specified points (vertices in "red" points, doesn't contain any "blue" points).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145498 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145498 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145498\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145605\" commentParentId=\"145492\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 21:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145605\" href=\"?#comment-145605\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145492\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145605\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145605\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>By the way, one could use only two sweeping lines (merging 1 with 2 and 3 with 4, but you would need two binary searches for determining both ends of the interval to query about.</p><p>Also a question to the author, when you say "find a convex polygon very very fast", what complexity do you mean? The input is O(N) so I guess it's above that, but is it like O(NLOGN) or O(N^2)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145605 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145605 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145605\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145619\" commentParentId=\"145605\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 22:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145619\" href=\"?#comment-145619\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145605\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145619\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145619\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145619\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Your solution to Bonus task B is really nice :) Good job. I added it to the post.</p><p>You have to find a convex quadrilateral, not a convex polygon. And yes, this one can be done very very quick. To be precise, no matter how big is N, you can find a convex quadrilateral in O(1). Suppose you have to read also the set of points, the complexity is still O(1). I hope it does not spoil too much :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145619 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145619 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145619\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145790\" commentParentId=\"145619\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2013 23:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145790\" href=\"?#comment-145790\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145619\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145790\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145790\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I got it!</p><p>Among any 5 points (with any 3 non-collinear, so there are no degenerate cases), there are some 4 which form a convex quadrilateral.</p><p>Suppose we take just 4 points. Either they form a convex quadrilateral, or there's one point (P4) that's inside the triangle T (with vertices P1..3) formed by the other 3. Now, take that case.</p><p>A quad. is convex iff its diagonals intersect. So if the 5th point (P5) is outside T, then one of the triangle's sides and segment P4-P5 intersect, so there's a convex quad. defined by them.</p><p>Now, take the situation when the P5 is inside T, which is split by P4 into 3 smaller triangles (by segments P1-P4, P2-P4, P3-P4). P5 must be in one of them (w.l.o.g. in P1P2P4). And again, the segment P3-P5 must cross one of the segments P1-P4 and P2-P4, so we have a convex quadrilateral.</p><p>What we need to do is: read the first 5 points of the list, try all possible quadrilaterals formed by them and check which one (there may be more than 1, but we only need one) is convex. Since we work on N=5, time is O(1). Tada!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145790 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145790 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145790\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145792\" commentParentId=\"145790\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2013 23:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145792\" href=\"?#comment-145792\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145790\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145792\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145792\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yep, this is the solution :)</p><p>Anyway, this is a Ramsey theory problem, which was studied for convex N-gons also. You can read details <a href=\"https://en.wikipedia.org/wiki/Happy_Ending_problem\">here</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145792 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145792 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145792\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145807\" commentParentId=\"145792\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 00:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145807\" href=\"?#comment-145807\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145792\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145807\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145807\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ooh, the generalization's nice! This will go to a slovak math training for sure (hehehe, let them suffer :D)!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145807 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145807 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145807\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146062\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lucaspala\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lucaspala\" title=\"Newbie lucaspala\" class=\"rated-user user-gray\">lucaspala</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 21:04\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146062\" href=\"?#comment-146062\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146062\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"119656\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146062\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Regarding problem C |ai - aj| for each i != j by S2, the answer is (N – 1)! * S1 + (N – 1)! * S2 / N!. In this formula i didn't understand that why they divide to N!. I will be pleasant if someone helps me.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146062 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146062 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146062\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146127\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Phicar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48358/avatar/9b2275bdec5496ef.jpg'/> </a>\n <div><a href=\"/profile/Phicar\" title=\"Pupil Phicar\" class=\"rated-user user-green\">Phicar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 09:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146127\" href=\"?#comment-146127\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146127\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48358\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146127\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can use Inclusion Exclusion without all that stuff, just using the number of -1's that appeared and the number of numbers that may be fixed points...just do the math as you want to compute the derrangements and you would get something like: </p><p><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1439932beeefe50c45c12a6529cdd88165b78e99.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> where n is the number of -1's and m is the number of positions that can be fixed points(the ones that have a -1 and it's index is not already used)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146127 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146127 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146127\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147926\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/crookshanks\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/89212/avatar/139d67c85696cc59.jpg'/> </a>\n <div><a href=\"/profile/crookshanks\" title=\"Specialist crookshanks\" class=\"rated-user user-cyan\">crookshanks</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/10/2013 11:02\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147926\" href=\"?#comment-147926\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147926\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"89212\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147926\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>this is gotta be the best tutorial of any contest of #CF ..... very nice :D (Y)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147926 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147926 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147926\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"155448\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Vadim2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49195/avatar/6b6e0d05659bf599.jpg'/> </a>\n <div><a href=\"/profile/Vadim2\" title=\"Expert Vadim2\" class=\"rated-user user-blue\">Vadim2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/25/2013 16:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-155448\" href=\"?#comment-155448\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"155448\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49195\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-155448\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have a qustion for B div2. Is it true, that 4 dots in the answer will be the part of convex hull?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-155448 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-155448 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-155448\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"157979\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sbasrik\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/25889/avatar/3cac1cfe4afcc819.jpg'/> </a>\n <div><a href=\"/profile/sbasrik\" title=\"Expert sbasrik\" class=\"rated-user user-blue\">sbasrik</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/16/2014 23:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-157979\" href=\"?#comment-157979\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"157979\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"25889\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-157979\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could anyone explain why "A number A[x][y] appears in exactly (X – x + 1) * (Y – y + 1) terms of xor sum." in Div1D problem ? What does "formula (X – x + 1)*(Y – y + 1) " mean, how we find it ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-157979 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-157979 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-157979\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"157987\" commentParentId=\"157979\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/17/2014 00:02\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-157987\" href=\"?#comment-157987\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-157979\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"157987\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-157987\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You're interested, for each element A[x][y], how many submatrixes it influences. So, if by (1, 1, a, b) I denote xor sum of all elements in submatrix (1, 1, a, b), how many (1, 1, a, b) do contain cell (x, y)?</p><p>You can see a submatrix (1, 1, a, b) contains cell (x, y) if a >= x and b >= y. So a can be in set {x, x + 1, ...., X} and b can be in set {y, y + 1, ..., Y}. First set contains X — x + 1 values and second one contains Y — y + 1 values. Choosing a and b is independent, even if I fix an a, the b can still take any value. Using rule of product, you get the number of matrixes (1, 1, a, b) which contain (x, y) is (X — x + 1) * (Y — y + 1).</p><p>Let cnt be number of submatrixes (1, 1, a, b) which contain (x, y). If cnt is even, number cancel each other in xor sum, so no need to xor A[x][y]. If cnt is odd, exactly one A[x][y] will remain, other cnt — 1 will cancel each other, since cnt — 1 is even number.</p><p>Now saying for each cell (x, y) you xor-ed value A[x][y] each time (x, y) appears in a submatrix (1, 1, a, b) is equivalent to say for each submatrix (1, 1, a, b) you xor-ed values of all elements it contains. Is it clear why? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-157987 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-157987 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-157987\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158007\" commentParentId=\"157987\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sbasrik\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/25889/avatar/3cac1cfe4afcc819.jpg'/> </a>\n <div><a href=\"/profile/sbasrik\" title=\"Expert sbasrik\" class=\"rated-user user-blue\">sbasrik</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/17/2014 01:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158007\" href=\"?#comment-158007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-157987\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"25889\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, now it is pretty clear, I got it exactly. Thanks a lot for spending time to explain it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"208781\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mochow\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/93201/avatar/bd3960384748e28.jpg'/> </a>\n <div><a href=\"/profile/mochow\" title=\"Specialist mochow\" class=\"rated-user user-cyan\">mochow</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2015 01:43\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-208781\" href=\"?#comment-208781\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"208781\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"93201\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-208781\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for this great tutorial. I am very satisfied specially at problem E of div2. The problem was fun. And so the dp solution was. :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-208781 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-208781 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-208781\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"255114\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/satyam\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/satyam\" title=\"Expert satyam\" class=\"rated-user user-blue\">satyam</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/07/2015 10:01\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-255114\" href=\"?#comment-255114\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"255114\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"136753\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-255114\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think there's a minor error in BubbleSortGraph's problem statement and editorial:</p><p>It is written:</p><p><code>if a[i] > a[i + 1] then add an undirected edge in G between a[i] and a[i + 1]</code></p><p>But, the edge should be between indexes i and i+1 instead of a[i] and a[i+1], consider this example:</p><p>2 3 2 6 8</p><p>The LIS here is: 2 3 6 8 , but there's an edge between 3 and 2 as indexes 2 and 3 are an inversion.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-255114 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-255114 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-255114\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"255140\" commentParentId=\"255114\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/satyam\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/satyam\" title=\"Expert satyam\" class=\"rated-user user-blue\">satyam</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/07/2015 12:41\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-255140\" href=\"?#comment-255140\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-255114\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"255140\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"136753\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-255140\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry, it's correct. I didn't notice that the elements are distinct.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-255140 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-255140 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-255140\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"366009\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/parthlathiya\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/256087/avatar/b8298fb0719d686.jpg'/> </a>\n <div><a href=\"/profile/parthlathiya\" title=\"Expert parthlathiya\" class=\"rated-user user-blue\">parthlathiya</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2017 03:46\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-366009\" href=\"?#comment-366009\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"366009\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"366009\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-10\"\r\n data-commentUserId=\"256087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-366009\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For 340D Bubble Sort Graph: <strong>Simple</strong> algoritham for LIS (Time complexity — O(nlogn) ) — Without using binary indexed tree,you just need to maintain one array. <a href=\"http://www.geeksforgeeks.org/longest-monotonically-increasing-subsequence-size-n-log-n/\">http://www.geeksforgeeks.org/longest-monotonically-increasing-subsequence-size-n-log-n/</a></p><p>Why downvotes?</p><p>My accepted solution using LIS(TC: nlogn), Without using binary indexed tree, <a href=\"//codeforces.com/contest/340/submission/27713075\">http://codeforces.com/contest/340/submission/27713075</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-366009 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-366009 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-366009\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"389733\" commentParentId=\"366009\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sagarthecoder2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/496991/avatar/61d8d75ce582d9ea.jpg'/> </a>\n <div><a href=\"/profile/sagarthecoder2\" title=\"Specialist sagarthecoder2\" class=\"rated-user user-cyan\">sagarthecoder2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/07/2017 19:39\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-389733\" href=\"?#comment-389733\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-366009\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"389733\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"496991\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-389733\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I couldn't understand,how 340D is related to longest increasing subsequence??? please reply me clearly .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-389733 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-389733 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-389733\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"389749\" commentParentId=\"389733\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/parthlathiya\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/256087/avatar/b8298fb0719d686.jpg'/> </a>\n <div><a href=\"/profile/parthlathiya\" title=\"Expert parthlathiya\" class=\"rated-user user-blue\">parthlathiya</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/07/2017 21:21\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-389749\" href=\"?#comment-389749\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-389733\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"389749\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"256087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-389749\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Read lemma 2 in above editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-389749 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-389749 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-389749\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"512615\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/praveenojha33\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/687087/avatar/f4330bc8d9012dda.jpg'/> </a>\n <div><a href=\"/profile/praveenojha33\" title=\"Expert praveenojha33\" class=\"rated-user user-blue\">praveenojha33</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2019 23:28\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-512615\" href=\"?#comment-512615\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"512615\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"687087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-512615\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In question B, Maximum Area Quadrilateral, Can anyone explain the solution more clearly ( The image in editorial is also unavailable ) specially the corner case. Thank You</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-512615 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-512615 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-512615\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8826\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8826 = true;\r\nvar lastPreviewContent8826 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8826] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8826] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8810\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8810, _tta: Codeforces.tta(), topicRevisionId: 31487, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8810\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8810, _tta: Codeforces.tta(), topicRevisionId: 31487, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:20</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128747b98c775b3',t:'MTY5NjcwNTk0MC4yMTkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1731,"cells":{"problem_id":{"kind":"string","value":"341E"},"contest":{"kind":"string","value":"341"},"problem":{"kind":"string","value":"E"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"E. Candies Game"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Candies Game</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub is playing an uncommon game. Initially, he has <span class=\"tex-span\"><i>n</i></span> boxes, numbered 1, 2, 3, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>n</i></span>. Each box has some number of candies in it, described by a sequence <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>. The number <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span> represents the number of candies in box <span class=\"tex-span\"><i>k</i></span>. </p><p>The goal of the game is to move all candies into <span class=\"tex-font-style-bf\">exactly</span> two boxes. The rest of <span class=\"tex-span\"><i>n</i> - 2</span> boxes must contain <span class=\"tex-font-style-bf\">zero</span> candies. Iahub is allowed to do several (possible zero) moves. At each move he chooses two different boxes <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span>, such that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>a</i><sub class=\"lower-index\"><i>j</i></sub></span>. Then, Iahub moves from box <span class=\"tex-span\"><i>j</i></span> to box <span class=\"tex-span\"><i>i</i></span> exactly <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> candies. Obviously, when two boxes have equal number of candies, box number <span class=\"tex-span\"><i>j</i></span> becomes empty.</p><p>Your task is to give him a set of moves such as Iahub to archive the goal of the game. If Iahub can't win the game for the given configuration of boxes, output -1. Please note that in case there exist a solution, you don't need to print the solution using minimal number of moves.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">3 ≤ <i>n</i> ≤ 1000</span>). The next line contains <span class=\"tex-span\"><i>n</i></span> non-negative integers: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> — sequence elements. It is guaranteed that sum of all numbers in sequence <span class=\"tex-span\"><i>a</i></span> is up to <span class=\"tex-span\">10<sup class=\"upper-index\">6</sup></span>. </p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In case there exists no solution, output -1. Otherwise, in the first line output integer <span class=\"tex-span\"><i>c</i></span> <span class=\"tex-span\">(0 ≤ <i>c</i> ≤ 10<sup class=\"upper-index\">6</sup>)</span>, representing number of moves in your solution. Each of the next <span class=\"tex-span\"><i>c</i></span> lines should contain two integers <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i>, <i>j</i> ≤ <i>n</i>, <i>i</i> ≠ <i>j</i>)</span>: integers <span class=\"tex-span\"><i>i</i></span>, <span class=\"tex-span\"><i>j</i></span> in the <span class=\"tex-span\"><i>k</i></span>th line mean that at the <span class=\"tex-span\"><i>k</i></span>-th move you will move candies from the <span class=\"tex-span\"><i>j</i></span>-th box to the <span class=\"tex-span\"><i>i</i></span>-th one.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>3 6 9<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/>2 3<br/>1 3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>0 1 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>0 1 1 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>For the first sample, after the first move the boxes will contain 3, 12 and 3 candies. After the second move, the boxes will contain 6, 12 and 0 candies. Now all candies are in exactly 2 boxes.</p><p>For the second sample, you can observe that the given configuration is not valid, as all candies are in a single box and they should be in two boxes. Also, any move won't change the configuration, so there exists no solution.</p><p>For the third sample, all candies are already in 2 boxes. Hence, no move is needed.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"39f741ec9ed3784bf4e3d5ae1ae41256\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"fb99ade5650f069f8c493acef1270657c082b773\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='39f741ec9ed3784bf4e3d5ae1ae41256'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F341%2Fproblem%2FE%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='39f741ec9ed3784bf4e3d5ae1ae41256'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/341\">Codeforces Round 198 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='39f741ec9ed3784bf4e3d5ae1ae41256'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/341/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Constructive algorithms\">\r\n constructive algorithms\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *3000\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='39f741ec9ed3784bf4e3d5ae1ae41256'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3426\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='39f741ec9ed3784bf4e3d5ae1ae41256'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3426\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8748\" title=\"Codeforces Round #198\" target=\"_blank\">Codeforces Round #198</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1830:1831\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/8755\" title=\"Tutorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1835\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/341\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/341/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/341/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/341/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/341/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/341/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/341/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/341/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_6a61013919b12e56702c82f19b9a0b897ce5cedb\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Candies Game</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub is playing an uncommon game. Initially, he has <span class=\"tex-span\"><i>n</i></span> boxes, numbered 1, 2, 3, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>n</i></span>. Each box has some number of candies in it, described by a sequence <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>. The number <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span> represents the number of candies in box <span class=\"tex-span\"><i>k</i></span>. </p><p>The goal of the game is to move all candies into <span class=\"tex-font-style-bf\">exactly</span> two boxes. The rest of <span class=\"tex-span\"><i>n</i> - 2</span> boxes must contain <span class=\"tex-font-style-bf\">zero</span> candies. Iahub is allowed to do several (possible zero) moves. At each move he chooses two different boxes <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span>, such that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>a</i><sub class=\"lower-index\"><i>j</i></sub></span>. Then, Iahub moves from box <span class=\"tex-span\"><i>j</i></span> to box <span class=\"tex-span\"><i>i</i></span> exactly <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> candies. Obviously, when two boxes have equal number of candies, box number <span class=\"tex-span\"><i>j</i></span> becomes empty.</p><p>Your task is to give him a set of moves such as Iahub to archive the goal of the game. If Iahub can't win the game for the given configuration of boxes, output -1. Please note that in case there exist a solution, you don't need to print the solution using minimal number of moves.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">3 ≤ <i>n</i> ≤ 1000</span>). The next line contains <span class=\"tex-span\"><i>n</i></span> non-negative integers: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> — sequence elements. It is guaranteed that sum of all numbers in sequence <span class=\"tex-span\"><i>a</i></span> is up to <span class=\"tex-span\">10<sup class=\"upper-index\">6</sup></span>. </p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In case there exists no solution, output -1. Otherwise, in the first line output integer <span class=\"tex-span\"><i>c</i></span> <span class=\"tex-span\">(0 ≤ <i>c</i> ≤ 10<sup class=\"upper-index\">6</sup>)</span>, representing number of moves in your solution. Each of the next <span class=\"tex-span\"><i>c</i></span> lines should contain two integers <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i>, <i>j</i> ≤ <i>n</i>, <i>i</i> ≠ <i>j</i>)</span>: integers <span class=\"tex-span\"><i>i</i></span>, <span class=\"tex-span\"><i>j</i></span> in the <span class=\"tex-span\"><i>k</i></span>th line mean that at the <span class=\"tex-span\"><i>k</i></span>-th move you will move candies from the <span class=\"tex-span\"><i>j</i></span>-th box to the <span class=\"tex-span\"><i>i</i></span>-th one.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />3 6 9<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br />2 3<br />1 3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />0 1 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />0 1 1 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>For the first sample, after the first move the boxes will contain 3, 12 and 3 candies. After the second move, the boxes will contain 6, 12 and 0 candies. Now all candies are in exactly 2 boxes.</p><p>For the second sample, you can observe that the given configuration is not valid, as all candies are in a single box and they should be in two boxes. Also, any move won't change the configuration, so there exists no solution.</p><p>For the third sample, all candies are already in 2 boxes. Hence, no move is needed.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:25</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bd3dba7e7b77',t:'MTY5NjY0NjAwNS40NzUwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Constructive algorithms\", \"Greedy algorithms\"]"},"short_tags":{"kind":"string","value":"[\"constructive algorithms\", \"greedy\", \"*3000\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8755"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"63d3318cfac089ece0c498e9cb121ecd\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #198 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #198 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='63d3318cfac089ece0c498e9cb121ecd'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8755\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='63d3318cfac089ece0c498e9cb121ecd'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:41</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:41</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='63d3318cfac089ece0c498e9cb121ecd'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/fchirica\">fchirica</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/fchirica\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/fchirica\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/fchirica\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/fchirica\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/fchirica\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/fchirica\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/fchirica\" style=\"text-decoration:none;color:black !important;\">fchirica's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8810\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8755\"> <p>Codeforces Round #198 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a>,\r\n <span class=\"format-humantime\" title=\"Aug/30/2013 23:23\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h2><a href=\"/contest/340/problem/A\" title=\"Codeforces Round 198 (Div. 2)\">340A - The Wall</a></h2><p>You are given a range <span class=\"tex-span\">[<i>A</i>, <i>B</i>]</span>. You're asked to compute fast how many numbers in the range are divisible by both <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>. I'll present here an <span class=\"tex-span\"><i>O</i>(<i>log</i>(<i>max</i>(<i>x</i>, <i>y</i>))</span> solution. We made tests low so other not optimal solutions to pass as well. The solution refers to the original problem, where <span class=\"tex-span\"><i>x</i>, <i>y</i> ≤ 10<sup class=\"upper-index\">9</sup></span>. </p><p>Firstly, we can simplify the problem. Suppose we can calculate how many numbers are divisible in range <span class=\"tex-span\">[1, <i>X</i>]</span> by both <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>. Can this solve our task? The answer is yes. All numbers in range <span class=\"tex-span\">[1, <i>B</i>]</span> divisible by both numbers should be counted, except the numbers lower than <span class=\"tex-span\"><i>A</i></span> (1, 2, ..., A — 1). But, as you can see, numbers lower than A divisible by both numbers are actually numbers from range [1, A — 1]. So the answer of our task is f(B) — f(A — 1), where f(X) is how many numbers from 1, 2, ..., X are divisible by both x and y.</p><p>For calculate in <span class=\"tex-span\"><i>O</i>(<i>log</i>(<i>max</i>(<i>x</i>, <i>y</i>))</span> the f(X) we need some math. If you don't know about it, please read firstly about least common multiple. Now, what will be the lowest number divisible by both x and y. The answer is least common multiple of x and y. Let's note it by <span class=\"tex-span\"><i>M</i></span>. The sequence of the numbers divisible by both x and y is <span class=\"tex-span\"><i>M</i></span>, <span class=\"tex-span\">2 * <i>M</i></span>, <span class=\"tex-span\">3 * <i>M</i></span> and so on. As a proof, suppose a number z is divisible by both x and y, but it is not in the above sequence. If a number is divisible by both x and y, it will be divisible by M also. If a number is divisible by M, it will be in the above sequence. Hence, the only way a number to be divisible by both x and y is to be in sequence <span class=\"tex-span\"><i>M</i></span>, <span class=\"tex-span\">2 * <i>M</i></span>, <span class=\"tex-span\">3 * <i>M</i></span>, ...</p><p>The f(X) calculation reduces to finding the number of numbers from sequence <span class=\"tex-span\"><i>M</i></span>, <span class=\"tex-span\">2 * <i>M</i></span>, <span class=\"tex-span\">3 * <i>M</i></span>, ... lower or equal than X. It's obvious that if a number h * M is greater than X, so will be (h + 1) * M, (h + 2) * M and so on. We actually need to find the greatest integer number h such as <span class=\"tex-span\"><i>h</i> * <i>M</i> ≤ <i>X</i></span>. The numbers we're looking for will be <span class=\"tex-span\">1 * <i>M</i>, 2 * <i>M</i>, ..., <i>h</i> * <i>M</i></span> (so their count will be <span class=\"tex-span\"><i>h</i></span>). The number h is actually [X / M], where [number] denotes the integer part of [number]. Take some examples on paper, you'll see why it's true.</p><p>The only thing not discussed is how to calculate the number M given 2 number x and y. You can use this formula <span class=\"tex-span\"><i>M</i> = <i>x</i> * <i>y</i> / <i>gcd</i>(<i>x</i>, <i>y</i>)</span>. For calculate gcd(x, y) you can use Euclid's algorithm. Its complexity is <span class=\"tex-span\"><i>O</i>(<i>log</i>(<i>max</i>(<i>x</i>, <i>y</i>))</span>, so this is the running time for the entire algorithm. </p><p>Official solution: <a href=\"/contest/340/submission/4383403\" title=\"Submission 4383403 by fchirica\">4383403</a></p><h2><a href=\"/contest/340/problem/B\" title=\"Codeforces Round 198 (Div. 2)\">340B - Maximal Area Quadrilateral</a></h2><p>I want to apologize for not estimating the real difficulty of this task. It turns out that it was more complicated than we thought it might be. Let's start explanation.</p><p>Before reading this, you need to know what is signed area of a triangle (also called cross product or ccw function). Without it, this explanation will make no sense. </p><p>The first thing we note is that a quadrilateral self intersecting won't have maximum area. I'll show you this by an image made by my "talents" in Paint :) As you can see, if a quadrilateral self intersects, it can be transformed into one with greater area. </p><p><img alt=\" \" src=\"/predownloaded/0e/1b/0e1b599b731a7c44948324132a0282ab4de2d724.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Each quadrilateral has 2 diagonals: connecting 1st and 3rd point and connecting 2nd and 4th point. A diagonal divides a plane into 2 subplanes. Suppose diagonal is AB. A point X can be in one of those two subplanes: that making cross product positive and that making cross product negative. A point is in "positive" subplane if ccw(X, A, B) > 0 and in "negative" subplane ccw(X, A, B) < 0. Note that according to the constraints of the task, ccw(X, A, B) will never be 0.</p><p>Let's make now the key observation of the task. We have a quadrilateral. Suppose AB is one of diagonals and C and D the other points from quadrilateral different by A and B. If the current quadrilateral could have maximal area, then one of points from C and D needs to be in "positive subplane" of AB and the other one in "negative subplane". What would happen if C and D will be in the same subplane of AB? The quadrilateral will self intersect. If it will self intersect, it won't have maximal area. "A picture is worth a thousand words" — this couldn't fit better in this case :) Note that the quadrilateral from the below image is A-C-B-D-A.</p><p><img alt=\" \" src=\"https://imageshack.us/a/img42/9976/dwkn.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Out task reduces to fix a diagonal (this taking O(N ^ 2) time) and then choose one point from the positive and the negative subplane of the diagonal. I'll say here how to choose the point from the positive subplane. That from negative subplane can be chosen identically. The diagonal and 3rd point chosen form a triangle. As we want quadrilateral to have maximal area, we need to choose 3rd point such as triangle makes the maximal area. As the positive and negative subplanes are disjoint, the choosing 3rd point from each of them can be made independently. Hence we get O(N ^ 3) complexity. A tricky case is when you choose a diagonal but one of the subplanes is empty. In this case you have to disregard the diagonal and move to the next one. </p><p>Official solution: <a href=\"/contest/340/submission/4383413\" title=\"Submission 4383413 by fchirica\">4383413</a></p><h2><a href=\"/contest/340/problem/C\" title=\"Codeforces Round 198 (Div. 2)\">340C - Tourist Problem</a></h2><p>Despite this is a math task, the only math formula we'll use is that number of permutations with <span class=\"tex-span\"><i>n</i></span> elements is <span class=\"tex-span\"><i>n</i>!</span>. From this one, we can deduce the whole task.</p><p>The average formula is sum_of_all_routes / number_of_routes. As each route is a permutation with n elements, number_of_routes is <span class=\"tex-span\"><i>n</i>!</span>. Next suppose you have a permutation of a: p1, p2, …, pn. The sum for it will be p1 + |p2 – p1| + … + |pn – pn-1|. The sum of routes will be the sum for each possible permutation. </p><p>We can calculate sum_of_all routes in two steps: first time we calculate sums like “p1” and then we calculate sums like “|p2 – p1| + … + |pn – pn-1|” for every existing permutation. </p><p><strong>First step</strong> Each element of <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, …, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> can appear on the first position on the routes and needs to be added as much as it appears. Suppose I fixed an element X for the first position. I can fill positions 2, 3, .., n – 1 in (n – 1)! ways. Why? It is equivalent to permuting n – 1 elements (all elements except X). So sum_of_all = <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span> * (n – 1)! + <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span> * (n – 1)! + … * <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> * (n – 1)! = (n – 1)! * (<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span> + <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span> + … + <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>).</p><p><strong>Second step</strong> For each permutation, for each position j between 1 and n – 1 we need to compute |<span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>j</i></sub></span> — <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"></sub>(<i>j</i> + 1)</span>|. Similarly to first step, we observe that only elements from <span class=\"tex-span\"><i>a</i></span> can appear on consecutive positions. We fix 2 indices i and j. We’re interested in how many permutations do <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> appear before <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i></sub></span>. We fix k such as on a permutation p, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> appears on position k and <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i></sub></span> appears on a position k + 1. In how many ways can we fix this? n – 1 ways (1, 2, …, n – 1). What’s left? A sequence of (n – 2) elements which can be permuted independently. So the sum of second step is |<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> - <i>a</i><sub class=\"lower-index\"><i>j</i></sub></span>| * (n – 1) * (n – 2)!, for each i != j. If I note (<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span> + <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span> + … + <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>) by S1 and |<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> - <i>a</i><sub class=\"lower-index\"><i>j</i></sub></span>| for each i != j by S2, the answer is (N – 1)! * S1 + (N – 1)! * S2 / N!. By a simplification, the answer is (S1 + S2) / N.</p><p>The only problem remained is how to calculate S2. Simple iteration won’t enter in time limit. Let’s think different. For each element, I need to make sum of differences between it and all smaller elements in the array a. As well, I need to make sum of all different between bigger elements than it and it. I’ll focus on the first part. I sort increasing array a. Suppose I’m at position <span class=\"tex-span\"><i>i</i></span>. I know that (i – 1) elements are smaller than <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. The difference is simply (i — 1) * <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> — sum_of_elements_before_position_i. Sum of elements before position i can be computed when iterating i. Let’s call the obtained sum Sleft. I need to calculate now sum of all differences between an element and bigger elements than it. This sum is equal to Sleft. As a proof, for an element <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, calculating the difference <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i></sub></span> — <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> when <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i></sub></span> > <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is equivalent to calculating differences between <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i></sub></span> and a smaller element of it (in this case <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>). That’s why Sleft = Sright.</p><p>As a conclusion, the answer is (S1 + 2 * Sleft) / N. For make fraction irreducible, you can use Euclid's algorithm. The complexity of the presented algorithm is <span class=\"tex-span\"><i>O</i>(<i>N</i> * <i>logN</i>)</span>, necessary due of sorting. Sorting can be implemented by count sort as well, having a complexity of O(maximalValue), but this is not necessary.</p><p>Official solution: <a href=\"/contest/340/submission/4383420\" title=\"Submission 4383420 by fchirica\">4383420</a></p><h2><a href=\"/contest/340/problem/D\" title=\"Codeforces Round 198 (Div. 2)\">340D - Bubble Sort Graph</a></h2><p>A good way to approach this problem is to notice that you can't build the graph. In worst case, the graph will be built in <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">2</sup>)</span> complexity, which will time out. Also, notice that "maximal independent set" is a NP-Hard task, so even if you can build the graph you can't continue from there. So, the correct route to start is to think of graph's properties instead of building it. After sketching a little on the paper, you should find this property:</p><p><strong>Lemma 1</strong> Suppose we choose 2 indices i and j, such as i < j. We'll have an edge on the graph between vertices <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i></sub></span> if and only if <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> > <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i></sub></span>. We'll call that i and j form an inversion in the permutation. </p><p><strong>Proof</strong> We assume we know the proof that bubble sort does sort correctly an array. To proof lemma 1, we need to show two things.</p> <ol> <li>Every inversion will be swapped by bubble sort.</li> <li>For each i < j when <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> < <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i></sub></span>, bubble sort will NOT swap this elements.</li> </ol><p>To proof 1, if bubble sort wouldn't swap an inversion, the sequence wouldn't be sorted. But we know that bubble sort always sorts a sequence, so all inversions will be swapped. Proofing 2 is trivial, just by looking at the code.</p><p>So far we've got how the graph G is constructed. Let's apply it in maximal independent set problem.</p><p><strong>Lemma 2</strong> A maximal independent set of graph G is a longest increasing sequence for permutation a. </p><p><strong>Proof</strong>: Suppose we have a set of indices <span class=\"tex-span\"><i>i</i>1</span> < <span class=\"tex-span\"><i>i</i>2</span> < ... <span class=\"tex-span\"><i>ik</i></span> such as <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i>1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i>2</sub></span>, ..., <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ik</i></sub></span> form an independent set. Then, anyhow we'd choose <span class=\"tex-span\"><i>d</i></span> and <span class=\"tex-span\"><i>e</i></span>, there won't exist an edge between <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>id</i></sub></span> and <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ie</i></sub></span>. According to proof 1, this only happens when <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>id</i></sub></span> < <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ie</i></sub></span>. Hence, an independent set will be equivalent to an increasing sequence of permutation a. The maximal independent set is simply the maximal increasing sequence of permutation a.</p><p>The task reduces to find longest increasing sequence for permutation <span class=\"tex-span\"><i>a</i></span>. This is a classical problem which can be solved in <span class=\"tex-span\"><i>O</i>(<i>N</i> * <i>logN</i>)</span>. <a href=\"//codeforces.com/blog/entry/8761\">Here</a> is an interesting discussion about how to do it. </p><h2><a href=\"/contest/340/problem/E\" title=\"Codeforces Round 198 (Div. 2)\">340E - Iahub and Permutations</a></h2><p>In this task, author's intended solution is an O(N ^ 2) dp. However, during testing <a class=\"rated-user user-orange\" href=\"/profile/Gerald\" title=\"Master Gerald\">Gerald</a> fount a solution using principle of inclusion and exclusion. We've thought to keep both solutions. We're sorry if you say the problem was well-known, but for both me and the author of the task, it was first time we saw it.</p><p><strong>Dynamic programming solution</strong></p><p>After reading the sequence, we can find which elements are deleted. Suppose we have in a set D all deleted elements. I'll define from now on a "free position" a position which has -1 value, so it needs to be completed with a deleted element. </p><p>We observe that some elements from D can appear on all free positions of permutation without creating a fixed point. The other elements from D can appear in all free positions except one, that will create the fixed point. It's intuitive that those two "classes" don't influence in the same way the result, so they need to be treated separated.</p><p>So from here we can get the dp state. Let dp(n, k) = in how many ways can I fill (n + k) free positions, such as n elements from D can be placed anywhere in the free position and the other k elements can be placed in all free positions except one, which will create the fixed point. As we'll prove by the recurrences, we are not interested of the values from elements of D. Instead, we'll interested in their property: if they can(not) appear in all free positions.</p><p>If k = 0, the problem becomes straight-forward. The answer for dp(n, 0) will be n!, as each permutation of (n + 0) = n numbers is valid, because all numbers can appear on all free positions. We can also calculate dp(n, 1). This means we are not allowed to place an element in a position out of (n + 1) free positions. However, we can place it in the other n positions. From now we get n elements which can be placed anywhere in the n free positions left. Hence, dp(n, 1) = n! * n.</p><p>We want to calculate dp(n, k) now, k > 1. Our goal is to reduce the number k, until find something we know how to calculate. That is, when k becomes 0 or 1 problem is solved. Otherwise, we want to reduce the problem to a problem when k becomes 0 or 1. I have two cases. In a first case, I take a number from numbers which can be placed anywhere in order to reduce the numbers which can form fixed points. In the second case, I take a number from those which can form fixed points in order to make the same goal as in the first case. Let's analyze them.</p><p>Case 1. Suppose X is the first free position, such as in the set of k numbers there exist one which cannot be placed there (because it will make a fixed point). Obviously, this position exist, otherwise k = 0. Also obviously, this position will need to be completed with a term when having a solution. In this case, I complete position X with one of n numbers. This will make number equal to X from the k numbers set to become a number which can be placed anywhere. So I "loose" one number which can be placed anywhere, but I also "gain" one. As well, I loose one number which can form a fixed point.</p><p>Hence dp(n, k) += n * dp(n, k — 1).</p><p>Case 2. In this case position X will be completed with one number from the k numbers set. All numbers which can form fixed points can appear there, except number having value equal to X. So there are k — 1 of them. I choose an arbitrary number Y from those k — 1 to place on the position X. This time I "loose" two numbers which could form fixed points: X and Y. As well, I "gain" one number which can be placed anywhere: X.</p><p>Hence dp(n, k) += (k — 1) * dp(n + 1, k — 2).</p><p><strong>TL;DR</strong></p><p>dp[N][0]=N!</p><p>dp[N][1]=N*dp[N][0]</p><p>dp[N][K]=N*dp[N][K-1]+(K-1)*dp[N+1][K-2] for K>=2</p><p>This recurrences can be computed by classical dp or by memoization. I'll present <a class=\"rated-user user-red\" href=\"/profile/DamianS\" title=\"Grandmaster DamianS\">DamianS</a>'s source, which used memoization. As you can see, it's very short and easy to implement. <a href=\"http://pastie.org/8286348\">Link</a></p><p><strong>Inclusion and exclusion principle</strong></p><p>I'll present here an alternative to the dynamic programming solution. Let's calculate in <span class=\"tex-span\"><i>tot</i></span> the number of deleted numbers. Also, let's calculate in <span class=\"tex-span\"><i>fixed</i></span> the <strong>maximal number of fixed points a permutation can have</strong>. For calculate <span class=\"tex-span\"><i>fixed</i></span>, let's iterate with an index <span class=\"tex-span\"><i>i</i></span> each permutation position. We can have a fixed point on position <span class=\"tex-span\"><i>i</i></span> if element from position <span class=\"tex-span\"><i>i</i></span> was deleted (<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> = -1) and element i does not exist in sequence <span class=\"tex-span\"><i>a</i></span>. With other words, element <span class=\"tex-span\"><i>i</i></span> was deleted and now I want to add it back on position <span class=\"tex-span\"><i>i</i></span> to obtain maximal number of fixed points. </p><p>We iterate now an index <span class=\"tex-span\"><i>i</i></span> from <span class=\"tex-span\"><i>fixed</i></span> to <span class=\"tex-span\">0</span>. Let sol[i] = the number of possible permutations having <em>exactly</em> <span class=\"tex-span\"><i>i</i></span> fixed points. Obviously, sol[0] is the answer to our problem. Let's introduce a <a href=\"https://en.wikipedia.org/wiki/Combination\">combination</a> <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a4b0ae77c1b1e95e3cba7276cfb7fecdb99b4221.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> representing in how many ways I can choose k objects out of n. I have list of positions which can be transformed into fix points (they are <span class=\"tex-span\"><i>fixed</i></span> positions). I need to choose <span class=\"tex-span\"><i>i</i></span> of them. According to the above definition, I get sol[i] = <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4cbfc413bd52e416b1fb7c018581f2467cb5a712.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> . Next, I have to fill <span class=\"tex-span\"><i>tot</i> - <i>i</i></span> positions with remained elements. We'll consider for this moment valid each permutation of not used values. So, sol[i] = <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/37e8612bbe476531470cec72cae3f7df22b9b162.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> . Where is the problem to this formula?</p><p>The problem is that it's possible, when permuting (tot — i) remained elements to be added, one (or more) elements to form more (new) fixed points. But if somehow I can exclude (subtract) the wrong choices from sol[i], sol[i] will be calculated correctly. I iterate another index <span class=\"tex-span\"><i>j</i></span> from i + 1 to <span class=\"tex-span\"><i>fixed</i></span>. For each j, I'll calculate how many permutations I considered in sol[i] having <span class=\"tex-span\"><i>i</i></span> fixed points but actually they have <span class=\"tex-span\"><i>j</i></span>. I'll subtract from sol[i] this value calculated for each j. If I do this, obviously sol[i] will be calculated correctly.</p><p>Suppose we fixed a j. We know that exactly sol[j] permutations have j fixed points (as j > i, this value is calculated correctly). Suppose now I fix a permutation having j fixed points. For get the full result, I need to calculate for all sol[j] permutations. Happily, I can multiply result obtained for a single permutation with sol[j] and obtain the result for all permutations having j fixed points. So you have a permutation having j fixed points. The problem reduces to choosing i objects from a total of j. Why? Those i objects chosen are actually the positions considered in sol[i] to be ones having exactly i fixed points. But permutation has j fixed points. Quoting for above, "For each j, I'll calculate how many permutations I considered in sol[i] having <span class=\"tex-span\"><i>i</i></span> fixed points but actually they have <span class=\"tex-span\"><i>j</i></span>" . This is exactly what algorithm does. </p><p>To sum up in a "LaTeX" way, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c44c16c69547f33183270573042717c9036b496b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>We can compute binomial coefficients using Pascal's triangle. Using inclusion and exclusion principle, we get <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">2</sup>)</span>. Please note that there exist an <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span> solution for this task, using inclusion and exclusion principle, but it's not necessary to get AC. I'll upload <a class=\"rated-user user-orange\" href=\"/profile/Gerald\" title=\"Master Gerald\">Gerald</a>'s source <a href=\"http://pastie.org/8287332\">here</a>.</p><h2><a href=\"/contest/341/problem/D\" title=\"Codeforces Round 198 (Div. 1)\">341D - Iahub and Xors</a></h2><p>The motivation of the problem is that x ^ x = 0. x ^ x ^ x… ^ x (even times) = 0</p><p><strong>Update per range, query per element</strong></p><p>When dealing with complicated problems, it's sometimes a good idea to try solving easier versions of them. Suppose you can query only one element each time (x0 = x1, y0 = y1). </p><p>To update a submatrix (x0, y0, x1, y1), I’ll do following operations. A[x0][y0] ^= val. A[x0][y1 + 1] ^= val. A[x1 + 1][y0] ^= val. A[x1 + 1][y1 + 1] ^= val.</p><p>To query about an element (X, Y), that element’s value will be the xor sum of submatrix A(1, 1, X, Y). Let’s take an example. I have a 6x6 matrix and I want to xor all elements from submatrix (2, 2, 3, 4) with a value. The below image should be explanatory how the method works:</p><p><img alt=\" \" src=\"https://imageshack.us/a/img96/8041/v83.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Next, by (1, 1, X, Y) I’ll denote xor sum for this submatrix.</p><p>“White” cells are not influenced by (2, 2, 3, 4) matrix, as matrix (1, 1, X, Y) with (X, Y) a white cell will never intersect it. “Red” cells are from the submatrix, the ones that need to be xor-ed. Note that for a red cell, (1, 1, X, Y) will contain the value we need to xor (as it will contain (2, 2)). Next, “blue” cells. For this ones (1, 1, X, Y) will contain the value we xor with, despite they shouldn’t have it. This is why both (2, 5) and (4, 2) will be xor-ed again by that value, to cancel the xor of (2, 2). Now it’s okay, every “blue” cell do not contain the xor value in their (1, 1, X, Y). Finally, the “green” cells. These ones are intersection between the 2 blue rectangles. This means, in their (1, 1, X, Y) the value we xor with appears 3 times (this means it is contained 1 time). For cancel this, we xor (4, 5) with the value. Now for every green cell (1, 1, X, Y) contains 4 equal values, which cancel each other.</p><p>You need a data structure do to the following 2 operations:</p> <ul> <li>Update an element (X, Y) (xor it with a value).</li> <li>Query about xor sum of (1, 1, X, Y).</li> </ul><p>Both operations can be supported by a Fenwick tree 2D. If you don't know this data structure, learn it and come back to this problem after you do this. </p><p><strong>Coming back to our problem</strong></p><p>Now, instead of finding an element, I want xor sum of a submatrix. You can note that xor sum of (x0, y0, x1, y1) is (1, 1, x1, y1) ^ (1, 1, x0 – 1, y1) ^ (1, 1, x1, y0 – 1) ^ (1, 1, x0 – 1, y0 – 1). This is a classical problem, the answer is (1, 1, x1, y1) from which I exclude what is not in the matrix: (1, 1, x0 – 1, y1) and (1, 1, x1, y0 – 1). Right now I excluded (1, 1, x0 – 1, y0 – 1) 2 times, so I need to add it one more time.</p><p>How to get the xor sum of submatrix (1, 1, X, Y)? In brute force approach, I’d take all elements (x, y) with 1 <= x <= X and 1 <= y <= Y and xor their values. Recall the definition of the previous problem, each element (x, y) is the xor sum of A(1, 1, x, y). So the answer is xor sum of all xor sums of A(1, 1, x, y), with 1 <= x <= X and 1 <= y <= Y.</p><p>We can rewrite that long xor sum. A number A[x][y] appears in exactly (X – x + 1) * (Y – y + 1) terms of xor sum. If (X – x + 1) * (Y – y + 1) is odd, then the value A[x][y] should be xor-ed to the final result exactly once. If (X — x + 1) * (Y — y + 1) is even, it should be ignored.</p><p>Below, you'll find 4 pictures. They are matrixes with X lines and Y columns. Each picture represents a case: (X odd, Y odd) (X even, Y even) (X even Y odd) (X odd Y even). Can you observe a nice pattern? Elements colored represent those for which (X – x + 1) * (Y – y + 1) is odd.</p><p><img alt=\" \" src=\"/predownloaded/97/11/9711911f5dae94dbd609bd95607f8abb0d241bcc.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> <img alt=\" \" src=\"/predownloaded/54/33/5433c6e1e6e6ac6345e898ea8a048a03404d4c1e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> <img alt=\" \" src=\"/predownloaded/b0/c2/b0c20ac42080a8eaad5a5c3d94241e916c12a767.bmp\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> <img alt=\" \" src=\"/predownloaded/20/e7/20e7d0f259c8907fe2e028da948843face8e5e3a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Yep, that's right! There are 4 cases, diving the matrix into 4 disjoint areas. When having a query of form (1, 1, X, Y) you only need specific elements sharing same parity with X and Y. This method works in O(4 * logN * logN) for each operation and is the indented solution. We keep 4 Fenwick trees 2D. We made tests such as solutions having complexity greater than O(4 * logN * logN) per operation to fail.</p><p>Here is our official solution: <a href=\"/contest/341/submission/4383473\" title=\"Submission 4383473 by fchirica\">4383473</a></p><h2><a href=\"/contest/341/problem/E\" title=\"Codeforces Round 198 (Div. 1)\">341E - Candies Game</a></h2><p><strong>Key observation</strong> Suppose you have 3 boxes containing A, B, C candies (A, B, C all greater than 0). Then, there will be always possible to empty one of boxes using some moves.</p><p><strong>Proof</strong> We can suppose that A <= B <= C. We need some moves such as the minimum from A, B, C will be zero. If we always keep the numbers in order A <= B <= C, it’s enough some moves such as A = 0. I’ll call this notation (A, B, C).</p><p>How can we prove that always exist such moves? We can use reductio ad absurdum to prove it. Let’s suppose, starting from (A, B, C) we can go to a state (A2, B2, C2). We suppose A2 (A2 > 0) is minimal from every state we can obtain. Since A2 is minimal number of coins that can be obtained and A2 is not zero, the statement is equivalent with we can’t empty one chest from configuration (A, B, C). Then, we can prove that from (A2, B2, C2) we can go to a state (A3, B3, C3), where A3 < A2. Obviously, this contradicts our assumption that A2 is minimal of every possible states. If A2 would be minimal, then there won’t be any series of moves to empty one chest. But A2 isn’t minimal, hence there always exist some moves to empty one chest.</p><p>Our algorithm so far:</p><p>void emptyOneBox(int A, int B, int C) {</p><p>if A is 0, then exit function.</p><p>Make some moves such as to find another state (A2, B2, C2) with A2 < A.</p><p>emptyOneBox (A2, B2, C2);</p><p>}</p><p>The only problem which needs to be proven now is: given a configuration (A, B, C) with A > 0, can we find another one (A2, B2, C2) such as A2 < A? The answer is always yes, below I’ll prove why.</p><p>Firstly, let’s imagine we want to constantly move candies into a box. It doesn't matter yet from where come the candies, what matters is candies arrive into the box. The box has initially X candies. After 1 move, it will have 2 * X candies. After 2 moves, it will have 2 * (2 * X) candies = 4 * X candies. Generally, after K moves, the box will contain 2^K * X candies.</p><p>We have A < B < C (if 2 numbers are equal, we can make a move and empty 1 box). If we divide B by A, we get from math that B = A * q + r. (obviously, always r < A). What if we can move exactly A * q candies from B to A? Then, our new state would be (r, B2, C2). We have now a number A2 = r, such as A2 < A.</p><p>How can we move exactly A * q coins? Let’s write q in base 2. Making that, q will be written as a sum of powers of 2. Suppose lim is the maximum number such as 2 ^ lim <= q. We get every number k from 0 to lim. For each k, I push into the first box (the box containing initially A candies) a certain number of candies. As proven before, I'll need to push (2 ^ k) * A candies. Let's take a look at the k-th bit from binary representation of q. If k-th bit is 1, B will be written as following: B = A * (2 ^ k + 2 ^ (other_power_1) + 2 ^ (other_power_2) + ...) + r. Hence, I'll be able to move A * (2 ^ k) candies from "B box" to "A box". Otherwise, I'll move from "C box" to "A box". It will be always possible to do this move, as C > B and I could do that move from B, too.</p><p>The proposed algorithm may look abstract, so let's take an example. </p><p>Suppose A = 3, B = 905 and C = 1024. Can we get less than 3 for this state?</p><p>B = 3 * 301 + 2. B = 3 * (100101101)2 + 2.</p><p>K = 0: we need to move (2^0) * 3 coins into A. 0th bit of q is 1, so we can move from B to A.</p><p>A = 6, B = 3 * (100101100)2 + 2 C = 1024</p><p>K = 1: we need to move (2 ^ 1) * 3 coins into A. Since 1th bit of q is already 0, we have to move from C.</p><p>A = 12, B = 3 * (100101100)2 + 2 C = 1018</p><p>K = 2: we need to move (2 ^ 2) * 3 coins into A. 2nd bit of q is 1, so we can move from B.</p><p>A = 24, B = 3 * (100101000)2 + 2 C = 1018</p><p>K = 3: we need to move (2 ^ 3) * 3 coins into A. 3nd bit of q is 1, so we can move from B.</p><p>A = 48, B = 3 * (100100000)2 + 2 C = 1018</p><p>K = 4. we need to move (2 ^ 4) * 3 coins into A. 4th bit of q is 0, we need to move from C.</p><p>A = 96, B = 3 * (100100000)2 + 2 C = 970</p><p>K = 5. we need to move (2 ^ 5) * 3 coins into A. 5th bit of q is 1, so we need to move from B.</p><p>A = 192, B = 3 * (100000000)2 + 2 C = 970</p><p>K = 6 we need to move (2 ^ 6) * 3 coins into A. We mve them from C.</p><p>A = 384 B = 3 * (100000000)2 + 2 C = 778</p><p>K = 7 we need to move (2 ^ 7) * 3 coins into A. We move them from C</p><p>A = 768 B = 3 * (100000000)2 + 2 C = 394</p><p>K=8 Finally, we can move our last 1 bit from B to A.</p><p>A = 1536 B = 3 * (000000000)2 + 2 C = 394</p><p>A = 1536 B = (3 * 0 + 2) C = 394</p><p>In the example, from (3, 905, 1024) we can arrive to (2, 394, 1536). Then, with same logic, we can go from (2, 394, 1536) to (0, X, Y), because 394 = 2 * 197 + 0.</p><p>This is how you could write emptyOneBox() procedure. The remained problem is straight-forward: if initially there are zero or one boxes having candies, the answer is "-1". Otherwise, until there are more than 2 boxes having candies, pick 3 boxes arbitrary and apply emptyOneBox(). </p><p>Here is a source implementing the algorithm. <a href=\"/contest/341/submission/4383485\" title=\"Submission 4383485 by fchirica\">4383485</a></p><h2>BONUS</h2><p>Instead of a conclusion, I'll post here related problems to the ones used in the round. :) Please note that some of them might be more easier / complicated than level of difficulty used in the round. Feel free to think of them / ask help / discuss them in the comment section :)</p><p><strong>Div2 A</strong> Suppose <span class=\"tex-span\"><i>x</i>, <i>y</i>, <i>A</i>, <i>B</i> ≤ 10<sup class=\"upper-index\">9</sup></span>. Instead of being asked how many bricks are colored with both red and pink in range <span class=\"tex-span\">[<i>A</i>, <i>B</i>]</span>, you're asked how many bricks are colored with at least one color. After you solve this one, solve the same problem, but instead of having 2 persons painting, you have k persons (<span class=\"tex-span\"><i>k</i> ≤ 20</span>). <a href=\"//codeforces.com/blog/entry/8755#comment-144971\">Solution</a> by <a class=\"rated-user user-violet\" href=\"/profile/Enchom\" title=\"Candidate Master Enchom\">Enchom</a></p><p><strong>Div2 B</strong> Given a very long list of special points, can you find quickly a convex special quadrilateral? Can you find very very quickly? :) Also, can you find maximal area of a special convex quadrilateral in time better than <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">4</sup>)</span>? Solutions for <a href=\"//codeforces.com/blog/entry/8755#comment-145790\">first problem</a> and <a href=\"//codeforces.com/blog/entry/8755#comment-145492\">second problem</a> provided by <a class=\"rated-user user-violet\" href=\"/profile/Xellos\" title=\"Candidate Master Xellos\">Xellos</a> and <a class=\"rated-user user-violet\" href=\"/profile/Enchom\" title=\"Candidate Master Enchom\">Enchom</a></p><p><strong>Div2 D / Div1 B</strong> Suppose the reverse problem. You are given a bubble sort graph having <span class=\"tex-span\"><i>N</i></span> vertices and <span class=\"tex-span\"><i>M</i></span> edges. Find its independent maximal set. Can you achieve <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">2</sup>)</span> to do this? Does a solution in <span class=\"tex-span\"><i>O</i>((<i>N</i> + <i>M</i>) + <i>N</i> * <i>logN</i>)</span> exist? <a href=\"//codeforces.com/blog/entry/8755#comment-144890\">Solution</a> by <a class=\"rated-user user-blue\" href=\"/profile/CountZero\" title=\"Expert CountZero\">CountZero</a></p><p><strong>Div2 E / Div1 C</strong> Find a solution running in liniar time. <a href=\"//codeforces.com/blog/entry/8755#comment-144888\">Solution (dynamic programming)</a> by <a class=\"rated-user user-violet\" href=\"/profile/ivan100sic\" title=\"Candidate Master ivan100sic\">ivan100sic</a> . <a href=\"//codeforces.com/blog/entry/8748#comment-144745\">Solution (inclusion exclusion principle)</a> by <a class=\"rated-user user-violet\" href=\"/profile/eduardische\" title=\"Candidate Master eduardische\">eduardische</a></p><p><strong>Div1 D</strong> Suppose the 3D version of this problem. You have a 3D matrix and you perform same QUERY/UPDATE operations, but using 6 parameters (a submatrix is defined now all elements a[i][j][k] for which x0 <= i <= x1, y0 <= j <= y1, z0 <= k <= z1). Can you get a solution using <span class=\"tex-span\"><i>O</i>(<i>log</i><sup class=\"upper-index\">3</sup> * <i>N</i>)</span> per query, having constant 8? But for d dimensions, does an <span class=\"tex-span\"><i>O</i>(2<sup class=\"upper-index\"><i>d</i></sup> * (<i>log</i><sup class=\"upper-index\"><i>d</i></sup>)<i>n</i>)</span> algorithm per query exist? :) <a href=\"//codeforces.com/blog/entry/8755#comment-144896\">Solution</a> by <a class=\"rated-user user-blue\" href=\"/profile/Dwylkz\" title=\"Expert Dwylkz\">Dwylkz</a>.</p><p><strong>Div1 E</strong> In our algorithm, we pick arbitrary 3 boxes. Can you find some heuristics of picking 3 boxes to reduce number of moves? </p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/340\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 198 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/341\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 198 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-12457-8810\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"12457\",\n blogEntryId: \"8755\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=198\" class=\"tag notice\" style=\"text-decoration: none;\">198</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8810\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+130</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8810\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/fchirica\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/fchirica\">\n fchirica\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Aug/30/2013 23:23\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8755#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8755#comments\">\n 82\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8826\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (77)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144799\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SeyedParsa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35492/avatar/21825d7789df0352.jpg'/> </a>\n <div><a href=\"/profile/SeyedParsa\" title=\"Master SeyedParsa\" class=\"rated-user user-orange\">SeyedParsa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/30/2013 23:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144799\" href=\"?#comment-144799\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144799\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144799\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-12\"\r\n data-commentUserId=\"35492\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-12</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144799\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great! Thanks for the detailed and accurate Editorial! <br /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144799 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144799 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144799\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144803\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Tparsa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/75633/avatar/f3c171fa286900c.jpg'/> </a>\n <div><a href=\"/profile/Tparsa\" title=\"Expert Tparsa\" class=\"rated-user user-blue\">Tparsa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/30/2013 23:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144803\" href=\"?#comment-144803\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144803\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"75633\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144803\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144803 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144803 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144803\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144811\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 01:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144811\" href=\"?#comment-144811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Lemma2 of 340 D is a little sudden for me. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144811\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144813\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ilyakor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/359/avatar/ac6a84569fcf8a43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/ilyakor\" title=\"Grandmaster ilyakor\" class=\"rated-user user-red\">ilyakor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 02:29\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144813\" href=\"?#comment-144813\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144813\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"20\"\r\n data-commentUserId=\"359\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+20</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144813\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Regarding problem D.</p> <blockquote><p>We made tests such as solutions having complexity greater than O(4 * logN * logN) per operation to fail.</p> </blockquote><p>Well, 4 * logN * logN (nit — O() notation here is incorrect, i.e. O(10000f) = O(f)) per operation also fails if it is not Fenwick tree (e.g., 2-d segment tree). Also, it seems that even carefully implemented Fenwick solution in Java runs longer than 0.5s, so TL should be >1s. Did jury have a Java solution?</p><p>I'd like also to note that for Fenwick trees there exists a more general approach for range updates, which works, e.g., for sum instead of xor (see <a href=\"http://petr-mitrichev.blogspot.ru/2013/05/fenwick-tree-range-updates.html\">this post</a>).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144813 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144813 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144813\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144824\" commentParentId=\"144813\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KADR\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1028/avatar/9089397f80c0fe42.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/KADR\" title=\"Master KADR\" class=\"rated-user user-orange\">KADR</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 08:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144824\" href=\"?#comment-144824\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144813\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144824\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"1028\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144824\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've got AC with 2-D segment tree.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144824 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144824 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144824\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144827\" commentParentId=\"144824\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/R_R_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/8865/avatar/dcf74f648e40d250.jpg'/> </a>\n <div><a href=\"/profile/R_R_\" title=\"International Master R_R_\" class=\"rated-user user-orange\">R_R_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 09:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144827\" href=\"?#comment-144827\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144824\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144827\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144827\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"8865\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144827\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Does your code have complexity O(logn*logn) for queries? I always thought that 2D segment tree is O(n) for queries like (1,1,1,n)</p><p><strong>Edit</strong>: Sorry, now I understand :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144827 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144827 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144827\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144828\" commentParentId=\"144827\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KADR\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1028/avatar/9089397f80c0fe42.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/KADR\" title=\"Master KADR\" class=\"rated-user user-orange\">KADR</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 09:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144828\" href=\"?#comment-144828\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144827\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144828\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"1028\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144828\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One should distinguish 2-D segment tree and quad-tree. The first one has complexity <span class=\"tex-span\"><i>O</i>(<i>logN</i>·<i>logN</i>)</span> per query, while the second one works in <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span> per query.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144828 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144828 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144828\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144878\" commentParentId=\"144828\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rubengt01\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/rubengt01\" title=\"Pupil rubengt01\" class=\"rated-user user-green\">rubengt01</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 00:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144878\" href=\"?#comment-144878\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144828\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144878\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"120886\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144878\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I implemented a quad tree and it was TLE in 6th test case. Can you help me to understand why an update or a query in a Quad tree is O(n). My solution stops the recursion when the interval asked or updated is same to the interval of the node. If you know an online explanation please share it. Thanks for the help <a href=\"//codeforces.com/contest/341/submission/4390134\">http://codeforces.com/contest/341/submission/4390134</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144878 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144878 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144878\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145175\" commentParentId=\"144878\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pushkarmishra\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/90420/avatar/e2f7bd3c3a048f5a.jpg'/> </a>\n <div><a href=\"/profile/pushkarmishra\" title=\"Specialist pushkarmishra\" class=\"rated-user user-cyan\">pushkarmishra</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/08/2013 03:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145175\" href=\"?#comment-145175\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144878\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145175\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"90420\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145175\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>try querying a 1xN row. you will realize that you ultimately have to query N 1-unit squares. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145175 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145175 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145175\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144835\" commentParentId=\"144813\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mugurelionut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63702/avatar/45e4d5390c215090.jpg'/> </a>\n <div><a href=\"/profile/mugurelionut\" title=\"International Master mugurelionut\" class=\"rated-user user-orange\">mugurelionut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 13:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144835\" href=\"?#comment-144835\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144813\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144835\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"63702\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144835\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Are you sure that the approach mentioned in Petr's post can be generalized to 2D or more dimensions (for supporting range updates and range queries) ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144835 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144835 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144835\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144924\" commentParentId=\"144835\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/02/2013 09:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144924\" href=\"?#comment-144924\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144835\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144924\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144924\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I suppose it can: <a href=\"//codeforces.com/contest/341/submission/4391440\">http://codeforces.com/contest/341/submission/4391440</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144924 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144924 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144924\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145437\" commentParentId=\"144924\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Igor_Kudryashov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/519/avatar/8c47a77b761709b6.jpg'/> </a>\n <div><a href=\"/profile/Igor_Kudryashov\" title=\"International Master Igor_Kudryashov\" class=\"rated-user user-orange\">Igor_Kudryashov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/12/2013 14:30\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145437\" href=\"?#comment-145437\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144924\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145437\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145437\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"519\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145437\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It is interesting) It is writen in statememnt that number <span class=\"tex-span\"><i>v</i></span> from update query <span class=\"tex-span\"> ≤ 2<sup class=\"upper-index\">62</sup></span>, but your solution using only int got accepted.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145437 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145437 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145437\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146133\" commentParentId=\"145437\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/R_R_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/8865/avatar/dcf74f648e40d250.jpg'/> </a>\n <div><a href=\"/profile/R_R_\" title=\"International Master R_R_\" class=\"rated-user user-orange\">R_R_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 12:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146133\" href=\"?#comment-146133\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145437\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146133\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"8865\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146133\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maybe it's because only the parity of the number matter, so overflow doesn't affect the result?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146133 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146133 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146133\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144818\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SuprDewd\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/15989/avatar/30d83ec6ea29a050.jpg'/> </a>\n <div><a href=\"/profile/SuprDewd\" title=\"Candidate Master SuprDewd\" class=\"rated-user user-violet\">SuprDewd</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 03:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144818\" href=\"?#comment-144818\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144818\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"36\"\r\n data-commentUserId=\"15989\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+36</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144818\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Realizing that the "Bubble Sort Graph" problem was equivalent to finding the length of the longest increasing subsequence was a really nice "Aha!" moment for me. Great problems, thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144818 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144818 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144818\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144836\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lxyxynt\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4130/avatar/77800d1adbf53169.jpg'/> </a>\n <div><a href=\"/profile/lxyxynt\" title=\"Candidate Master lxyxynt\" class=\"rated-user user-violet\">lxyxynt</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 13:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144836\" href=\"?#comment-144836\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144836\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"4130\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144836\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Where are the pictures in 341D?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144836 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144836 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144836\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144955\" commentParentId=\"144836\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 13:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144955\" href=\"?#comment-144955\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144836\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144955\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144955\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>They work perfectly for me. I uploaded them at imageshack.us . Maybe you a problem with that server. Please, tell me a server for which the images will be visible to you and I'll upload there.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144955 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144955 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144955\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144963\" commentParentId=\"144955\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lxyxynt\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4130/avatar/77800d1adbf53169.jpg'/> </a>\n <div><a href=\"/profile/lxyxynt\" title=\"Candidate Master lxyxynt\" class=\"rated-user user-violet\">lxyxynt</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 17:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144963\" href=\"?#comment-144963\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144955\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144963\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4130\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144963\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you for your kind reply! it's visible to me now.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144963 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144963 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144963\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144844\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kyuubi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83590/avatar/b87432a652bb276.jpg'/> </a>\n <div><a href=\"/profile/Kyuubi\" title=\"Expert Kyuubi\" class=\"rated-user user-blue\">Kyuubi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 14:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144844\" href=\"?#comment-144844\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144844\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"83590\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144844\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For 340B I used the Gift Wrap alogirithm to compute a Convex Hull for the points, and then using a DP found the minimum Area that needs to be cut off from this Hull to form a quadrilateral. </p><p>Worst Case for Hull O(n^3) + DP O(n^2) Total execution time was 30ms</p><p>The only corner case was when the hull is composed of only 3 points. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144844 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144844 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144844\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144848\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 16:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144848\" href=\"?#comment-144848\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144848\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144848\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I found that most of the solutions marked correct for the problem 340D gave the answer 1 for the input</p><p>3 12 13 1</p><p>Whereas it should have been 2(maximal set can be {12,13}). Did the test cases miss something or am I making a really silly mistake here?</p><p>Can I hack solutions after the match has ended. If so could anyone please let me know.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144848 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144848 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144848\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144851\" commentParentId=\"144848\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 16:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144851\" href=\"?#comment-144851\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144848\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144851\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144851\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My bad :(. I just re-read the problem and found that the numbers can be <=n</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144851 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144851 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144851\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144856\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/HekpoMaH\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62637/avatar/38b1193a84b213e9.jpg'/> </a>\n <div><a href=\"/profile/HekpoMaH\" title=\"Specialist HekpoMaH\" class=\"rated-user user-cyan\">HekpoMaH</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 19:04\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144856\" href=\"?#comment-144856\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144856\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"62637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144856\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"//codeforces.com/blog/entry/8761\">http://codeforces.com/blog/entry/8761</a> PLS help!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144856 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144856 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144856\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144863\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Azat_Yusupov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30140/avatar/a9bdb2076a46d716.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Azat_Yusupov\" title=\"Candidate Master Azat_Yusupov\" class=\"rated-user user-violet\">Azat_Yusupov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 19:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144863\" href=\"?#comment-144863\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144863\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"30140\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144863\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks to author for the contest. It was the best raund I have ever seen.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144863 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144863 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144863\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144868\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hashbash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/66704/avatar/92e9040cf5324c99.jpg'/> </a>\n <div><a href=\"/profile/hashbash\" title=\"Specialist hashbash\" class=\"rated-user user-cyan\">hashbash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/31/2013 21:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144868\" href=\"?#comment-144868\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144868\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"66704\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144868\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you please elaborate on how the (i — 1) * ai = sum_of_elements_before_position_i in question 341C ???</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144868 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144868 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144868\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144958\" commentParentId=\"144868\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 15:50\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144958\" href=\"?#comment-144958\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144868\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144958\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144958\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For a fixed ai, you need to calculate sum of ai — aj, when aj < ai. If I sort sequence a in increasing order, then all elements aj < ai will be in positions {1, 2, ..., i — 1}. So I need to calculate ai — a1 + ai — a2 + ... ai — a(i-1). Ai appears (i — 1) times in this sum, so I re-write the sum being (i — 1) * ai — a1 — a2 — ... — a(i — 1). This is (i — 1) * ai — (a1 + a2 + ... + a(i — 1)). I need to sum for each i this expression. It can be computed in O(N), see my source for reference. There, sumBefore is (a1 + a2 + ... + a(i — 1)).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144958 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144958 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144958\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144959\" commentParentId=\"144958\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hashbash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/66704/avatar/92e9040cf5324c99.jpg'/> </a>\n <div><a href=\"/profile/hashbash\" title=\"Specialist hashbash\" class=\"rated-user user-cyan\">hashbash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 16:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144959\" href=\"?#comment-144959\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144958\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144959\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"66704\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144959\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for your reply.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144959 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144959 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144959\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144884\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/DieAnderen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/DieAnderen\" title=\"Specialist DieAnderen\" class=\"rated-user user-cyan\">DieAnderen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 01:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144884\" href=\"?#comment-144884\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144884\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"16\"\r\n data-commentUserId=\"106427\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+16</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144884\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try Geogebra to draw good Geometric figures. It's free.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144884 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144884 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144884\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144886\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/karan173\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/karan173\" title=\"Expert karan173\" class=\"rated-user user-blue\">karan173</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 02:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144886\" href=\"?#comment-144886\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144886\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53106\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144886\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For 340E, can't we just do dp[n][k] = n*dp[n-1][k] + k*dp[n][k-1] ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144886 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144886 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144886\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144887\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 05:05\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144887\" href=\"?#comment-144887\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144887\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144887\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>This is the most explanatory editorial I have ever seen on codeforces :) Really nice work guys :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144887 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144887 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144887\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144888\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ivan100sic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/26422/avatar/611ce74705dadb74.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/ivan100sic\" title=\"International Grandmaster ivan100sic\" class=\"rated-user user-red\">ivan100sic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 07:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144888\" href=\"?#comment-144888\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144888\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"26422\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144888\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well, turns out div2 E / div1 C has an even simpler O(N) solution. Take a look at <a class=\"rated-user user-blue\" href=\"/profile/problem-solved\" title=\"Expert problem-solved\">problem-solved</a>'s elegant <a href=\"//codeforces.com/contest/341/submission/4384292\">solution</a>, or perhaps <a href=\"//codeforces.com/contest/341/submission/4377177\">mine</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144888 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144888 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144888\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144892\" commentParentId=\"144888\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Solitary\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Solitary\" title=\"Expert Solitary\" class=\"rated-user user-blue\">Solitary</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 10:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144892\" href=\"?#comment-144892\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144888\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144892\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"126956\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144892\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just like the number of desarrangements of length n,right?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144892 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144892 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144892\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144900\" commentParentId=\"144888\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/karan173\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/karan173\" title=\"Expert karan173\" class=\"rated-user user-blue\">karan173</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 15:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144900\" href=\"?#comment-144900\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144888\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144900\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53106\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144900\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>please explain the solution.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144900 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144900 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144900\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145055\" commentParentId=\"144888\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/accidentallygivenfuck\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34459/avatar/c4e2278aa2ac1176.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/accidentallygivenfuck\" title=\"Expert accidentallygivenfuck\" class=\"rated-user user-blue\">accidentallygivenfuck</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/07/2013 10:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145055\" href=\"?#comment-145055\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144888\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145055\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34459\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145055\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you please tell, what <code>+(i-1)*D[i-2]</code> is needed for?<br />I had an idea like this (which got WA, I still dont know why). Here: </p> <pre><code>D[i] = ends*D[i-1] + (i-1)*D[i-1];\nD[i] = (ends+i-1)*D[i-1];\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145055 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145055 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145055\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145057\" commentParentId=\"145055\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/accidentallygivenfuck\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34459/avatar/c4e2278aa2ac1176.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/accidentallygivenfuck\" title=\"Expert accidentallygivenfuck\" class=\"rated-user user-blue\">accidentallygivenfuck</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/07/2013 10:41\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145057\" href=\"?#comment-145057\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145055\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145057\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145057\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34459\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145057\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>BTW, my idea is:<br />I place <span class=\"tex-span\"><i>i</i></span> in <span class=\"tex-span\"><i>i</i><sup class=\"upper-index\"><i>th</i></sup></span> position (which makes fixed point). Then for each <span class=\"tex-span\"><i>D</i>[<i>i</i> - 1]</span> permutations, I swap <span class=\"tex-span\"><i>i</i></span> with some other number, as none of the rest will make fixed point while in <span class=\"tex-span\"><i>i</i><sup class=\"upper-index\"><i>th</i></sup></span> position, and <span class=\"tex-span\"><i>i</i></span> won't make fixed point in any other position. So for each <span class=\"tex-span\"><i>D</i>[<i>i</i> - 1]</span> (correct) permutations, I have <span class=\"tex-span\">(<i>ends</i> + <i>i</i> - 1)</span> different numbers to swap <span class=\"tex-span\"><i>i</i></span> with and I get <code>D[i] = (ends+i-1)*D[i-1]</code>. But I miss something, something with <code>D[i-2]</code>. :(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145057 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145057 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145057\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144890\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 09:05\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144890\" href=\"?#comment-144890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div2 D Bonus <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> solution. If there is no edge between vertices <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> > <i>a</i><sub class=\"lower-index\"><i>j</i></sub></span>, then <span class=\"tex-span\"><i>i</i> > <i>j</i></span>, else <span class=\"tex-span\"><i>i</i> < <i>j</i></span>. One is easy to build the original sequence by applying any sorting algorithm with this comparator</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144890\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144975\" commentParentId=\"144890\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/04/2013 01:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144975\" href=\"?#comment-144975\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144890\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144975\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144975\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice solution. :) I didn't thought of that one. BTWs, for those interested there exist one way to build the sequence in linear time. You can google about research article: McConnell, Ross M.; Spinrad, Jeremy P. (1999), "Modular decomposition and transitive orientation"</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144975 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144975 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144975\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144896\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dwylkz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30502/avatar/462a9dcaf9fca2c4.jpg'/> </a>\n <div><a href=\"/profile/Dwylkz\" title=\"Specialist Dwylkz\" class=\"rated-user user-cyan\">Dwylkz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 12:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144896\" href=\"?#comment-144896\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144896\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144896\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"30502\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144896\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here is my solution for 341D.</p><p><strong>Define</strong>: "sum" stand for <span class=\"tex-span\"><i>xor</i></span> sum. <span class=\"tex-span\"> + , - </span> stand for <span class=\"tex-span\"><i>xor</i></span>. <span class=\"tex-span\"><i>a</i> * <i>b</i></span> means that apply <span class=\"tex-span\"><i>b</i> + <i>b</i></span> for <span class=\"tex-span\"><i>a</i> - 1</span> times.</p> <ol> <li><p>Notice that we could do <span class=\"tex-span\"> + </span> and <span class=\"tex-span\"> - </span> subtraction interval-wise.</p></li> <li><p>But Fenwick tree could only update per range and query per element or vice versa.</p></li> <li><p>If, for each element, say, <span class=\"tex-span\"><i>ft</i>(<i>x</i>, <i>y</i>)</span> hold the sum of prefix sum of the matrix <span class=\"tex-span\">(1, 1, <i>x</i>, <i>y</i>)</span> (ie. prefix sum of prefix sum of <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span>), then for each query, <span class=\"tex-span\"><i>ft</i>(<i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>) - <i>ft</i>(<i>x</i><sub class=\"lower-index\">0</sub> - 1, <i>y</i><sub class=\"lower-index\">1</sub>) - <i>ft</i>(<i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">0</sub> - 1) + <i>ft</i>(<i>x</i><sub class=\"lower-index\">0</sub> - 1, <i>y</i><sub class=\"lower-index\">0</sub> - 1)</span> would be the result. As the difference between prefix-sum is the sum of the corresponding interval.</p></li> <li><p>And it's easy to <span class=\"tex-span\"><i>xor</i></span> a <span class=\"tex-span\"><i>v</i></span> to elements in submatrix <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">0</sub>, <i>y</i><sub class=\"lower-index\">0</sub>, <i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>)</span>.</p></li> <li><p>Consider 1 dimension version of this problem. For a sequence <span class=\"tex-span\"><i>a</i></span>, the prefix sum of <span class=\"tex-span\"><i>x</i></span> is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0c328f79f88844c99902ced4f17316c1518417a8.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and the prefix sum of prefix sum of x is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/310eecfbb820cd40a1a8bd63ccbbd3f9119d208f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p></li> <li><p>Hence, all we have to do is to maintain an extra sequnce <span class=\"tex-span\"><i>i</i> * <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p></li> <li><p>Then expand method above to arbitrary dimension.</p></li> </ol><p>Here is an <a href=\"//codeforces.com/contest/341/submission/4391987\">implement</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144896 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144896 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144896\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145260\" commentParentId=\"144896\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pushkarmishra\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/90420/avatar/e2f7bd3c3a048f5a.jpg'/> </a>\n <div><a href=\"/profile/pushkarmishra\" title=\"Specialist pushkarmishra\" class=\"rated-user user-cyan\">pushkarmishra</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/09/2013 16:20\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145260\" href=\"?#comment-145260\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144896\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145260\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145260\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"90420\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145260\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can your method also be used if we have to perform the following operations on a 2D matrix:</p> <ol> <li>update x1, y1, x2, y2, k. in this operation, we add k to each element in sub-matrix x1, y1, x2, y2.</li> <li>query x1, y1, x2, y2. in this, we output the sum of all elements in sub-matrix x1, y1, x2, y2.</li> </ol><p>can the same logic be extended??</p><p>EDIT: Yes, it can be. thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145260 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145260 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145260\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145295\" commentParentId=\"145260\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dwylkz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30502/avatar/462a9dcaf9fca2c4.jpg'/> </a>\n <div><a href=\"/profile/Dwylkz\" title=\"Specialist Dwylkz\" class=\"rated-user user-cyan\">Dwylkz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/10/2013 05:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145295\" href=\"?#comment-145295\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145260\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145295\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145295\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30502\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145295\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes, and, it could be extended to 3 or more dimensions, too :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145295 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145295 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145295\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144899\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 15:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144899\" href=\"?#comment-144899\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144899\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144899\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nicely written tutorial, and really good round in my opinion, looking forward for the solution of problem 341E, and also loving the idea of Bonus problems, really good authors! Thank you for the lovely round! :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144899 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144899 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144899\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144902\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TsunamiNoLetGo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63066/avatar/2e9b4d0dfeda8d47.jpg'/> </a>\n <div><a href=\"/profile/TsunamiNoLetGo\" title=\"Master TsunamiNoLetGo\" class=\"rated-user user-orange\">TsunamiNoLetGo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2013 17:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144902\" href=\"?#comment-144902\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144902\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"63066\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144902\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>340-B maximum area quad is really tough to pass the time limit with python ! I can see no accepted solutions !!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144902 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144902 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144902\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144953\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/alibaba\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/alibaba\" title=\"Expert alibaba\" class=\"rated-user user-blue\">alibaba</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 12:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144953\" href=\"?#comment-144953\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144953\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144953\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"97169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144953\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem Div2 340E , in the case 2 : "Case 2. In this case position X will be completed with one number from the k numbers set..." if the position X with X is an used number, how the total number of elements which can be placed anywhere increase? For example n = 7 , -1 -1 4 2 -1 -1 -1 => N = 1 {3 } , K = 4 {1 , 5, 6, 7} , so if we put a number in K at position 2, the number of N will not increased!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144953 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144953 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144953\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144954\" commentParentId=\"144953\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 13:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144954\" href=\"?#comment-144954\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144953\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144954\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144954\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>X positions can be {1, 5, 6, 7}. Only those positions can create fixed points. Suppose we choose now arbitrary X = 1. I can place there numbers Y = {5, 6, 7}. Now, permutation will look like Y -1 4 2 -1 -1 -1. Obviously, 1 can be placed anywhere now, hence number N is increased.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144954 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144954 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144954\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144956\" commentParentId=\"144954\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/alibaba\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/alibaba\" title=\"Expert alibaba\" class=\"rated-user user-blue\">alibaba</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 15:22\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144956\" href=\"?#comment-144956\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144954\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144956\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"97169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144956\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you for your answer, but I am still not clear :D</p><p>About position number 2, which case it corresponding to? like in the above case -1 Y 4 2 -1 -1 -1 -> number N will not increased.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144956 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144956 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144956\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144957\" commentParentId=\"144956\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 15:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144957\" href=\"?#comment-144957\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144956\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144957\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144957\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144957\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You don't deal with it for the moment. You deal only with set of positions {1, 5, 6, 7}. Each time, you reduce one or two elements from the set (depending of choosing case 1 or case 2). When set has 0 or 1 element, then you can handle the other positions (see initialization of dp, it will handle position 2 also). As each time K decreases by 1 or 2, it's obvious sometime you'll be in the basic case, when you'll handle the other positions. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144957 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144957 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144957\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144961\" commentParentId=\"144957\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/alibaba\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/alibaba\" title=\"Expert alibaba\" class=\"rated-user user-blue\">alibaba</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 17:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144961\" href=\"?#comment-144961\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144957\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144961\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"97169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144961\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you :D will need time to digest it. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144961 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144961 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144961\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144971\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2013 23:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144971\" href=\"?#comment-144971\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144971\" revisionCount=\"9\" revision=\"9\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">9</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144971\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144971\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder if the authors will post the solutions to bonus problems after some time? :)</p><p>Anyway, here is my idea of the Div2 A — Bonus, sorry if there is much simpler solution, this is what i thought of :)</p><p>Let's say that the i-th painter will paint all bricks divisible by X[i]. I will assume that the least common multiple of X[1], X[2], X[3]...X[k] will fit in long long. (If it doesn't you can easily still solve it using the same method, it's just for the sake of simplicity). Let's define a certain colouring by a binary number. The <strong>1</strong>s in the binary number correspond to the colors that were surely used ( <strong>0</strong> doesn't necessary mean the colour isn't used ). For example for K=5, 10100 would define that surely the first and third colours were used in that colouring.</p><p>To get the answer we iterate over all possible colourings, and if the colouring contains odd number of ones, we add the amount of bricks that are coloured that way, otherwise we remove that amount. The solution has complexity O(2^k*log) if implemented good, because there are 2^k possible colourings and for each we need to find the least common multiple of the used colours to determine the amount of bricks that are coloured that way.</p><p>I know it sounds quite weird and at the moment i'm struggling to find a proof, but i have tested it and it works. If someone could provide a proof that would be great :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144971 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144971 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144971\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144972\" commentParentId=\"144971\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/04/2013 00:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144972\" href=\"?#comment-144972\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144971\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144972\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144972\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, I'll post my ideas for Bonus tasks if there are enough persons interested. :) This is a classic task solvable by inclusion and exclusion principle. If I understood well what your solution does, it uses exactly this principle. Google it and you'll find proof for your solution :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144972 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144972 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144972\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144974\" commentParentId=\"144972\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/04/2013 00:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144974\" href=\"?#comment-144974\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144972\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"144974\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"144974\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144974\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'd love to see the solutions, i've spent A LOT of time on those bonus problems :).</p><p>Here is what i consider to be my "proof" for the solution i described above :P</p><p><strong>Proof</strong></p><p>Let's imagine we are iterating the binary numbers in order of increasing amount of ones in them. If we are for example at the number 01010, then we want to count the bricks colored that way, exactly once. However we have already counted them when looking at binary numbers 01000 and 00010. So how many times exactly have we counted a given binary number? Well if the binary number has exactly P ones in it, then we have counted it C(1,P) times when looking at numbers with 1 one in them, C(2,P) times when looking at numbers with 2 ones in them and so on. However remember that we do not always add, we subtract too, so we get the following :</p><p>For a number with P ones in it, we have counted it exactly S times where <strong>S=C(1,P)-C(2,P)+C(3,P)-C(4,P)+C(5,P)...C(P-1,P).</strong></p><p>Well it took me quite a lot of time, but not that difficultly it can be proven that <strong>-C(0,P)+C(1,P)-C(2,P)+C(3,P)...C(P,P) equals 0</strong>, therefor obviously for odd P, S=0 and for even P — S=2. And since we want to count each colouring exactly ones, obviously for odd P, we add it once and for even P we subtract it.</p><p>C(K,N) = <a href=\"https://en.wikipedia.org/wiki/Binomial_coefficient\">binomial coefficient</a></p><p>It's a little bit clumsy but i made it myself because i haven't heard about inclusion-exclusion principle :)</p><p>P.S. Sorry for all those long posts, i just really liked the problems and spent a lot of time on them :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144974 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144974 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144974\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"144973\" commentParentId=\"144971\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sparik\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83327/avatar/226632cbc2cf9c5.jpg'/> </a>\n <div><a href=\"/profile/sparik\" title=\"Candidate Master sparik\" class=\"rated-user user-violet\">sparik</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/04/2013 00:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-144973\" href=\"?#comment-144973\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-144971\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"144973\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"83327\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-144973\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think this is the simplest solution. It uses inclusion-exclusion principle. <a href=\"http://www.spoj.com/problems/NGM2/\">This problem on SPOJ</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-144973 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-144973 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-144973\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145248\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akshayk0406\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/akshayk0406\" title=\"Pupil akshayk0406\" class=\"rated-user user-green\">akshayk0406</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/09/2013 14:05\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145248\" href=\"?#comment-145248\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145248\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4596\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145248\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem 340C</p><p>I didn't understand second step to calculate sum_of_all_routes. Can someone explain with the help of example.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145248 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145248 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145248\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145285\" commentParentId=\"145248\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Cer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Cer\" title=\"Specialist Cer\" class=\"rated-user user-cyan\">Cer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/09/2013 21:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145285\" href=\"?#comment-145285\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145248\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145285\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145285\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"119611\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145285\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>this step is to compute the sum of all possible differences |ai-aj| where (i != j) in all possible permutations.</p><p>consider we have the sequence a1, a2, a3, a4, a5, a6 and we want to get how many times a2 will come before a3 directly by keeping a1 a4 a5 a6 in this order as a subsequence I will list all those permutations that fullfill the last condition : a2 a3 a1 a4 a5 a6</p><p>a1 a2 a3 a4 a5 a6</p><p>a1 a4 a2 a3 a5 a6</p><p>a1 a4 a5 a2 a3 a6</p><p>a1 a4 a5 a6 a2 a3</p><p>and the number of those permutations is n-1 = 6-1 = 5. and those 5 times is when a1 a4 a5 a6 comes in this order and to compute how many times for all possible orders of a1 a4 a5 a6 then we multiply by (n-2)! = (6-2)! = 4! = 24 so the number of times that a2 a3 comes consecutivly is (n-1)*(n-2)! = (n-1)! and the sum of all differences |a2-a3| is (n-1)!*|a2-a3|. S2 is the sum of all differences |ai - aj| for each i != j .</p><p>to compute S2 : for each ai we want to compute the differece between it and all other elements aj where i != j and let us sort the given sequence a1 a2 a3 a4 a5 a6 in increasing order then the sum of all differences |ai — ak| where k<i is (i-1)*ai — (sum_of_elements_before_position_i) lets call this sum is slefti then we find slefti for each i and let sleft = sleft1 + sleft2 + sleft3 ..... + sleft6 = sum_of(slefti) for i= 1 to n when we compute sleft we find that sright = sleft where sright = sright1 + sright2 + .... + sright6 and we know that S2 = sleft + sright = 2*sleft </p><p>so the last result will be (S1 + S2) / n = (S1 + 2*sleft) / n and to make the fraction in simplest form we divide both of (S1+S2) and n on GCD((s1+s2),n)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145285 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145285 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145285\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145298\" commentParentId=\"145285\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akshayk0406\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/akshayk0406\" title=\"Pupil akshayk0406\" class=\"rated-user user-green\">akshayk0406</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/10/2013 09:05\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145298\" href=\"?#comment-145298\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145285\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145298\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4596\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145298\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks, that was very good explaination. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145298 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145298 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145298\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146123\" commentParentId=\"145285\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lucaspala\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lucaspala\" title=\"Newbie lucaspala\" class=\"rated-user user-gray\">lucaspala</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 08:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146123\" href=\"?#comment-146123\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145285\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146123\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"119656\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146123\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why they are dividing s2 * (n-1)! to n!? Please help me</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146123 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146123 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146123\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145492\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 01:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145492\" href=\"?#comment-145492\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145492\" revisionCount=\"6\" revision=\"6\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">6</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145492\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"15\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145492\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here is my idea on the Div2 B "Can you find maximal area convex quadrilateral", I spent a lot of time on it because it was the only problem that the author didn't have solution for :).</p><p>Its only theoretical, I haven't tested it because I am not able to write source now (I'm currently at the Balkan Olympiad), so if it is wrong please do not hate :)</p><p><strong>My solution</strong></p><p>Ok first, we need to find a way to check if a quadrilateral is convex while constructing it, and to do that we can simply use that quadrilateral's diagonals cross if and only if it's convex. Therefor if we find two crossing lines, created from 4 special points, we have a special convex quadrilateral.</p><p>Now as first step of our algorithm, we will take every two points and construct a line, let the points be A and B, then we will imagine its infinite continuation in the plane, and also two infinite lines perpendicular to our line and crossing it in the special points. That will divide the plane in 6 sections, but for the sake of simplicity we will look only on 3 of them (on one of the sides) because they are simetrical. Here is a picture (special points are red) :</p><p><img alt=\" \" src=\"/predownloaded/04/b2/04b22291765bdf15839e99944b5cddf8f1a31779.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>So we have three zones, blue, green and yellow. Now let's look at all other special points that are in one of those zones. We will do a few rotating sweeping lines to have some ordered sets of points. First sweeping line will start from point A to infinite in direction opposite to B paralel to AB and save all the points in the <strong>BLUE AREA ONLY</strong> , second line will start from point A to infinite being perpendicular to AB and will save all points in the <strong>GREEN AREA ONLY</strong>, third line is the same as the second but starts from B and rotates in the opposite direction, again saves all points in the <strong>GREEN AREA ONLY</strong>, and fourth and last line is same as the first, but start from B and saves all points in the <strong>YELLOW AREA ONLY</strong>. Here is a picture of the lines and their rotating directions :</p><p><img alt=\" \" src=\"/predownloaded/90/a1/90a16ea1ffdaec788c2b32e2c5c7fcb63738809b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>For each special point we will save the cross product it gives with line AB. So for each line we have four sets of points where the second and third actually contain the same points but with different orderings. We put those 4 sets in 4 RMQ structures so we could later get the highest of the cross products in some interval fast. Assuming we use roughly O(N*LOGN) for the sweeping lines and to build RMQ, and O(N^2) to fix a line, we have complexity of O(N^3*LOGN) for now.</p><p>Now let's proceed with our actual solution. We fix a line AB and a third point C. Now we want such point D so that AB and CD cross (being the diagonals of convex quadrilateral) and the cross product of D to the line AB is maximum. Let's look at a picture of points A,B and C :</p><p><img alt=\" \" src=\"/predownloaded/11/e9/11e9e5f8f9e2a5ad97396fb10016de0db20efdad.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Obviously for CD to cross AB, D must be in the area marked with white above. So now how to fast get the point with maximum cross product to AB in that white area? Well we have 3 different cases depending on the place of C in the initial 6 zones that I divided the plane into. Let's take a look.</p><p><strong>Case 1</strong></p><p>When C is on the other side of the <strong>blue area</strong></p><p><img alt=\" \" src=\"/predownloaded/8d/e1/8de155f6e990f50da4bd43c1d85ab26eca1c08e2.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>So obviously we want D to be in the pink area, pink area covers part of the green and part of the yellow areas. For the green area we can use the set of points from sweeping line 2. By binary we will find the first point that is in the pink area, and then get RMQ query for that suffix of the array of points. Same thing we can do with the yellow area, using the points from sweeping line 4. Therefor we can find the best point D in O(LOGN).</p><p><strong>Case 2</strong></p><p>When C is on the other side of the <strong>green area</strong></p><p><img alt=\" \" src=\"/predownloaded/09/73/09733f3479756bb9177f87b4ac6a78b0baa06449.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Now obviously we cover the whole green area, so we can just call a RMQ query of the whole range on any of the sweeping line 2 or 3, and for the blue part that is covered, we can again do binary and then RMQ query in points from sweep line 1, and the same thing for the yellow parts, with the points from sweep line 4.</p><p><strong>Case 3</strong></p><p>When C is on the other side of the <strong>yellow area</strong></p><p>I'm not gonna show a picture of that as it is really symmetrical to case 1, you just again use binary and RMQ query in sweep lines 1 and 3 for the blue and green parts that are covered.</p><p>Obviously each test case takes roughly O(LOGN) and fixing points A,B,C is O(N^3), so i think that solution would be O(N^3*LOGN) in general. I'm sorry if it is wrong i am unable to test it right now, but I really took a lot of time to explain it nicely (sorry if it isn't very understandable), so hope I helped :)</p><p>P.S. Sorry for the long post, I was excited to share my idea :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145492 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145492 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145492\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145493\" commentParentId=\"145492\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sweiss\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/sweiss\" title=\"Grandmaster sweiss\" class=\"rated-user user-red\">sweiss</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 01:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145493\" href=\"?#comment-145493\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145492\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145493\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"412\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145493\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>dude, you're awesome!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145493 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145493 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145493\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145496\" commentParentId=\"145492\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 01:44\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145496\" href=\"?#comment-145496\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145492\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145496\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145496\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Isn't the author's solution <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">3</sup>)</span>?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145496 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145496 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145496\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145497\" commentParentId=\"145496\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 01:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145497\" href=\"?#comment-145497\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145496\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145497\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145497\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145497\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Author's solution describes a solution for finding maximal area quadrilateral, however it doesn't guarantee it will be a convex one. In the bonus tasks the author asked if anyone could find a maximal area <strong>convex</strong> quadrilateral in less than O(N^4), because he couldn't find a solution, and I took it as a challenge. It is a bonus task :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145497 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145497 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145497\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145498\" commentParentId=\"145497\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 02:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145498\" href=\"?#comment-145498\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145497\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145498\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145498\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah, right. I didn't notice that. Seems quite tough to implement... well done.</p><p>And a challenge atop a challenge: yesterday's gym ACM training, problem I: find the largest convex <strong>polygon</strong> which doesn't contain any of additional specified points (vertices in "red" points, doesn't contain any "blue" points).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145498 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145498 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145498\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145605\" commentParentId=\"145492\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Enchom\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57870/avatar/e165ef41ac17de3b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Enchom\" title=\"Grandmaster Enchom\" class=\"rated-user user-red\">Enchom</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 21:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145605\" href=\"?#comment-145605\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145492\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145605\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57870\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145605\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>By the way, one could use only two sweeping lines (merging 1 with 2 and 3 with 4, but you would need two binary searches for determining both ends of the interval to query about.</p><p>Also a question to the author, when you say "find a convex polygon very very fast", what complexity do you mean? The input is O(N) so I guess it's above that, but is it like O(NLOGN) or O(N^2)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145605 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145605 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145605\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145619\" commentParentId=\"145605\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2013 22:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145619\" href=\"?#comment-145619\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145605\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145619\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145619\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145619\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Your solution to Bonus task B is really nice :) Good job. I added it to the post.</p><p>You have to find a convex quadrilateral, not a convex polygon. And yes, this one can be done very very quick. To be precise, no matter how big is N, you can find a convex quadrilateral in O(1). Suppose you have to read also the set of points, the complexity is still O(1). I hope it does not spoil too much :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145619 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145619 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145619\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145790\" commentParentId=\"145619\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2013 23:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145790\" href=\"?#comment-145790\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145619\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145790\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145790\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I got it!</p><p>Among any 5 points (with any 3 non-collinear, so there are no degenerate cases), there are some 4 which form a convex quadrilateral.</p><p>Suppose we take just 4 points. Either they form a convex quadrilateral, or there's one point (P4) that's inside the triangle T (with vertices P1..3) formed by the other 3. Now, take that case.</p><p>A quad. is convex iff its diagonals intersect. So if the 5th point (P5) is outside T, then one of the triangle's sides and segment P4-P5 intersect, so there's a convex quad. defined by them.</p><p>Now, take the situation when the P5 is inside T, which is split by P4 into 3 smaller triangles (by segments P1-P4, P2-P4, P3-P4). P5 must be in one of them (w.l.o.g. in P1P2P4). And again, the segment P3-P5 must cross one of the segments P1-P4 and P2-P4, so we have a convex quadrilateral.</p><p>What we need to do is: read the first 5 points of the list, try all possible quadrilaterals formed by them and check which one (there may be more than 1, but we only need one) is convex. Since we work on N=5, time is O(1). Tada!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145790 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145790 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145790\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145792\" commentParentId=\"145790\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2013 23:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145792\" href=\"?#comment-145792\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145790\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145792\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145792\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yep, this is the solution :)</p><p>Anyway, this is a Ramsey theory problem, which was studied for convex N-gons also. You can read details <a href=\"https://en.wikipedia.org/wiki/Happy_Ending_problem\">here</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145792 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145792 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145792\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145807\" commentParentId=\"145792\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 00:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145807\" href=\"?#comment-145807\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145792\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145807\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145807\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ooh, the generalization's nice! This will go to a slovak math training for sure (hehehe, let them suffer :D)!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145807 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145807 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145807\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146062\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lucaspala\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lucaspala\" title=\"Newbie lucaspala\" class=\"rated-user user-gray\">lucaspala</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 21:04\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146062\" href=\"?#comment-146062\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146062\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"119656\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146062\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Regarding problem C |ai - aj| for each i != j by S2, the answer is (N – 1)! * S1 + (N – 1)! * S2 / N!. In this formula i didn't understand that why they divide to N!. I will be pleasant if someone helps me.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146062 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146062 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146062\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146127\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Phicar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48358/avatar/9b2275bdec5496ef.jpg'/> </a>\n <div><a href=\"/profile/Phicar\" title=\"Pupil Phicar\" class=\"rated-user user-green\">Phicar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 09:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146127\" href=\"?#comment-146127\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146127\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48358\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146127\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can use Inclusion Exclusion without all that stuff, just using the number of -1's that appeared and the number of numbers that may be fixed points...just do the math as you want to compute the derrangements and you would get something like: </p><p><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1439932beeefe50c45c12a6529cdd88165b78e99.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> where n is the number of -1's and m is the number of positions that can be fixed points(the ones that have a -1 and it's index is not already used)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146127 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146127 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146127\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147926\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/crookshanks\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/89212/avatar/139d67c85696cc59.jpg'/> </a>\n <div><a href=\"/profile/crookshanks\" title=\"Specialist crookshanks\" class=\"rated-user user-cyan\">crookshanks</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/10/2013 11:02\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147926\" href=\"?#comment-147926\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147926\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"89212\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147926\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>this is gotta be the best tutorial of any contest of #CF ..... very nice :D (Y)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147926 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147926 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147926\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"155448\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Vadim2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49195/avatar/6b6e0d05659bf599.jpg'/> </a>\n <div><a href=\"/profile/Vadim2\" title=\"Expert Vadim2\" class=\"rated-user user-blue\">Vadim2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/25/2013 16:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-155448\" href=\"?#comment-155448\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"155448\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49195\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-155448\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have a qustion for B div2. Is it true, that 4 dots in the answer will be the part of convex hull?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-155448 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-155448 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-155448\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"157979\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sbasrik\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/25889/avatar/3cac1cfe4afcc819.jpg'/> </a>\n <div><a href=\"/profile/sbasrik\" title=\"Expert sbasrik\" class=\"rated-user user-blue\">sbasrik</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/16/2014 23:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-157979\" href=\"?#comment-157979\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"157979\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"25889\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-157979\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could anyone explain why "A number A[x][y] appears in exactly (X – x + 1) * (Y – y + 1) terms of xor sum." in Div1D problem ? What does "formula (X – x + 1)*(Y – y + 1) " mean, how we find it ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-157979 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-157979 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-157979\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"157987\" commentParentId=\"157979\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/17/2014 00:02\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-157987\" href=\"?#comment-157987\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-157979\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"157987\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-157987\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You're interested, for each element A[x][y], how many submatrixes it influences. So, if by (1, 1, a, b) I denote xor sum of all elements in submatrix (1, 1, a, b), how many (1, 1, a, b) do contain cell (x, y)?</p><p>You can see a submatrix (1, 1, a, b) contains cell (x, y) if a >= x and b >= y. So a can be in set {x, x + 1, ...., X} and b can be in set {y, y + 1, ..., Y}. First set contains X — x + 1 values and second one contains Y — y + 1 values. Choosing a and b is independent, even if I fix an a, the b can still take any value. Using rule of product, you get the number of matrixes (1, 1, a, b) which contain (x, y) is (X — x + 1) * (Y — y + 1).</p><p>Let cnt be number of submatrixes (1, 1, a, b) which contain (x, y). If cnt is even, number cancel each other in xor sum, so no need to xor A[x][y]. If cnt is odd, exactly one A[x][y] will remain, other cnt — 1 will cancel each other, since cnt — 1 is even number.</p><p>Now saying for each cell (x, y) you xor-ed value A[x][y] each time (x, y) appears in a submatrix (1, 1, a, b) is equivalent to say for each submatrix (1, 1, a, b) you xor-ed values of all elements it contains. Is it clear why? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-157987 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-157987 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-157987\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158007\" commentParentId=\"157987\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sbasrik\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/25889/avatar/3cac1cfe4afcc819.jpg'/> </a>\n <div><a href=\"/profile/sbasrik\" title=\"Expert sbasrik\" class=\"rated-user user-blue\">sbasrik</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/17/2014 01:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158007\" href=\"?#comment-158007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-157987\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"25889\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, now it is pretty clear, I got it exactly. Thanks a lot for spending time to explain it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"208781\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mochow\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/93201/avatar/bd3960384748e28.jpg'/> </a>\n <div><a href=\"/profile/mochow\" title=\"Specialist mochow\" class=\"rated-user user-cyan\">mochow</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2015 01:43\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-208781\" href=\"?#comment-208781\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"208781\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"93201\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-208781\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for this great tutorial. I am very satisfied specially at problem E of div2. The problem was fun. And so the dp solution was. :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-208781 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-208781 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-208781\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"255114\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/satyam\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/satyam\" title=\"Expert satyam\" class=\"rated-user user-blue\">satyam</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/07/2015 10:01\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-255114\" href=\"?#comment-255114\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"255114\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"136753\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-255114\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think there's a minor error in BubbleSortGraph's problem statement and editorial:</p><p>It is written:</p><p><code>if a[i] > a[i + 1] then add an undirected edge in G between a[i] and a[i + 1]</code></p><p>But, the edge should be between indexes i and i+1 instead of a[i] and a[i+1], consider this example:</p><p>2 3 2 6 8</p><p>The LIS here is: 2 3 6 8 , but there's an edge between 3 and 2 as indexes 2 and 3 are an inversion.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-255114 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-255114 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-255114\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"255140\" commentParentId=\"255114\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/satyam\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/satyam\" title=\"Expert satyam\" class=\"rated-user user-blue\">satyam</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/07/2015 12:41\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-255140\" href=\"?#comment-255140\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-255114\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"255140\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"136753\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-255140\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry, it's correct. I didn't notice that the elements are distinct.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-255140 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-255140 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-255140\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"366009\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/parthlathiya\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/256087/avatar/b8298fb0719d686.jpg'/> </a>\n <div><a href=\"/profile/parthlathiya\" title=\"Expert parthlathiya\" class=\"rated-user user-blue\">parthlathiya</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2017 03:46\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-366009\" href=\"?#comment-366009\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"366009\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"366009\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-10\"\r\n data-commentUserId=\"256087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-366009\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For 340D Bubble Sort Graph: <strong>Simple</strong> algoritham for LIS (Time complexity — O(nlogn) ) — Without using binary indexed tree,you just need to maintain one array. <a href=\"http://www.geeksforgeeks.org/longest-monotonically-increasing-subsequence-size-n-log-n/\">http://www.geeksforgeeks.org/longest-monotonically-increasing-subsequence-size-n-log-n/</a></p><p>Why downvotes?</p><p>My accepted solution using LIS(TC: nlogn), Without using binary indexed tree, <a href=\"//codeforces.com/contest/340/submission/27713075\">http://codeforces.com/contest/340/submission/27713075</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-366009 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-366009 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-366009\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"389733\" commentParentId=\"366009\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sagarthecoder2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/496991/avatar/61d8d75ce582d9ea.jpg'/> </a>\n <div><a href=\"/profile/sagarthecoder2\" title=\"Specialist sagarthecoder2\" class=\"rated-user user-cyan\">sagarthecoder2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/07/2017 19:39\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-389733\" href=\"?#comment-389733\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-366009\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"389733\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"496991\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-389733\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I couldn't understand,how 340D is related to longest increasing subsequence??? please reply me clearly .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-389733 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-389733 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-389733\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"389749\" commentParentId=\"389733\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/parthlathiya\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/256087/avatar/b8298fb0719d686.jpg'/> </a>\n <div><a href=\"/profile/parthlathiya\" title=\"Expert parthlathiya\" class=\"rated-user user-blue\">parthlathiya</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/07/2017 21:21\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-389749\" href=\"?#comment-389749\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-389733\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"389749\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"256087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-389749\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Read lemma 2 in above editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-389749 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-389749 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-389749\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"512615\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/praveenojha33\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/687087/avatar/f4330bc8d9012dda.jpg'/> </a>\n <div><a href=\"/profile/praveenojha33\" title=\"Expert praveenojha33\" class=\"rated-user user-blue\">praveenojha33</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2019 23:28\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-512615\" href=\"?#comment-512615\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"512615\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"687087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-512615\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In question B, Maximum Area Quadrilateral, Can anyone explain the solution more clearly ( The image in editorial is also unavailable ) specially the corner case. Thank You</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-512615 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-512615 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-512615\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8826\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8826 = true;\r\nvar lastPreviewContent8826 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8826] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8826] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8810\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8810, _tta: Codeforces.tta(), topicRevisionId: 31487, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8810\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8810, _tta: Codeforces.tta(), topicRevisionId: 31487, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:20</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128747b98c775b3',t:'MTY5NjcwNTk0MC4yMTkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1732,"cells":{"problem_id":{"kind":"string","value":"342A"},"contest":{"kind":"string","value":"342"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Xenia and Divisors"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Xenia and Divisors</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Xenia the mathematician has a sequence consisting of <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\"><i>n</i></span> is divisible by 3) positive integers, each of them is at most 7. She wants to split the sequence into groups of three so that for each group of three <span class=\"tex-span\"><i>a</i>, <i>b</i>, <i>c</i></span> the following conditions held:</p><ul> <li> <span class=\"tex-span\"><i>a</i> < <i>b</i> < <i>c</i></span>; </li><li> <span class=\"tex-span\"><i>a</i></span> divides <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>b</i></span> divides <span class=\"tex-span\"><i>c</i></span>. </li></ul><p>Naturally, Xenia wants each element of the sequence to belong to exactly one group of three. Thus, if the required partition exists, then it has <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4de0f387b35d0865b1f96d528b2f1b06fb6f1903.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> groups of three.</p><p>Help Xenia, find the required partition or else say that it doesn't exist.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(3 ≤ <i>n</i> ≤ 99999)</span> — the number of elements in the sequence. The next line contains <span class=\"tex-span\"><i>n</i></span> positive integers, each of them is at most 7.</p><p>It is guaranteed that <span class=\"tex-span\"><i>n</i></span> is divisible by 3.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If the required partition exists, print <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4de0f387b35d0865b1f96d528b2f1b06fb6f1903.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> groups of three. Print each group as values of the elements it contains. You should print values in increasing order. Separate the groups and integers in groups by whitespaces. If there are multiple solutions, you can print any of them.</p><p>If there is no solution, print -1.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>6<br/>1 1 1 2 2 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6<br/>2 2 1 1 4 6<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 2 4<br/>1 2 6<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"bc4b334fe2152269d0f11174f9ae2797\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"91a1e137bf92bd9ed30f9398e9597722ab5e17d3\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='bc4b334fe2152269d0f11174f9ae2797'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F342%2Fproblem%2FA%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='bc4b334fe2152269d0f11174f9ae2797'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/342\">Codeforces Round 199 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='bc4b334fe2152269d0f11174f9ae2797'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/342/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1200\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='bc4b334fe2152269d0f11174f9ae2797'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3438\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='bc4b334fe2152269d0f11174f9ae2797'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3438\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8795\" title=\"Codeforces Round #199 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1837:1838\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/8800\" title=\"Tutorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1840\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/342\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/342/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/342/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/342/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/342/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/342/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/342/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/342/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_41df0a61a178551c9b48a3108445a206c31f021b\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Xenia and Divisors</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Xenia the mathematician has a sequence consisting of <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\"><i>n</i></span> is divisible by 3) positive integers, each of them is at most 7. She wants to split the sequence into groups of three so that for each group of three <span class=\"tex-span\"><i>a</i>, <i>b</i>, <i>c</i></span> the following conditions held:</p><ul> <li> <span class=\"tex-span\"><i>a</i> < <i>b</i> < <i>c</i></span>; </li><li> <span class=\"tex-span\"><i>a</i></span> divides <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>b</i></span> divides <span class=\"tex-span\"><i>c</i></span>. </li></ul><p>Naturally, Xenia wants each element of the sequence to belong to exactly one group of three. Thus, if the required partition exists, then it has <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4de0f387b35d0865b1f96d528b2f1b06fb6f1903.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> groups of three.</p><p>Help Xenia, find the required partition or else say that it doesn't exist.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(3 ≤ <i>n</i> ≤ 99999)</span> — the number of elements in the sequence. The next line contains <span class=\"tex-span\"><i>n</i></span> positive integers, each of them is at most 7.</p><p>It is guaranteed that <span class=\"tex-span\"><i>n</i></span> is divisible by 3.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If the required partition exists, print <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4de0f387b35d0865b1f96d528b2f1b06fb6f1903.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> groups of three. Print each group as values of the elements it contains. You should print values in increasing order. Separate the groups and integers in groups by whitespaces. If there are multiple solutions, you can print any of them.</p><p>If there is no solution, print -1.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>6<br />1 1 1 2 2 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6<br />2 2 1 1 4 6<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 2 4<br />1 2 6<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:26</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bd45ce481628',t:'MTY5NjY0NjAwNi44OTcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Greedy algorithms\", \"Implementation problems, programming technics, simulation\"]"},"short_tags":{"kind":"string","value":"[\"greedy\", \"implementation\", \"*1200\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8800"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"779401b049eaea220649756fcc29cd29\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #199 (Div. 2) Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #199 (Div. 2) Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='779401b049eaea220649756fcc29cd29'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8800\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='779401b049eaea220649756fcc29cd29'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:41</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:41</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='779401b049eaea220649756fcc29cd29'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/HolkinPV\">HolkinPV</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/HolkinPV\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/HolkinPV\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/HolkinPV\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/HolkinPV\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/HolkinPV\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/HolkinPV\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/HolkinPV\" style=\"text-decoration:none;color:black !important;\">HolkinPV's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8855\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8800\"> <p>Codeforces Round #199 (Div. 2) Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/HolkinPV\" title=\"Candidate Master HolkinPV\" class=\"rated-user user-violet\">HolkinPV</a>,\r\n <span class=\"format-humantime\" title=\"Sep/07/2013 14:37\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/342/problem/A\" title=\"Codeforces Round 199 (Div. 2)\">342A - Xenia and Divisors</a></p><p>In this problem you should guess that exists only three valid groups of three </p><p>1) 1, 2, 4 </p><p>2) 1, 2, 6 </p><p>3) 1, 3, 6 </p><p>(You can see that integers 5 and 7 are bad).</p><p>So, we will greedy take these groups of three. If some integers will be not used, the answer is -1. In other case, print found answer.</p><p><a href=\"/contest/342/problem/B\" title=\"Codeforces Round 199 (Div. 2)\">342B - Xenia and Spies</a></p><p>The problem is solved by greedy algorithm. We will pass the note only in correct direction. Also, if we can pass the note at the current moment of time, we do it. In other case, we will hold it and don't give it to neighbors (we can make this action at any moment of time). Obviously this algorithm is correct. You should only implement it carefully.</p><p><a href=\"/contest/342/problem/C\" title=\"Codeforces Round 199 (Div. 2)\">342C - Cupboard and Balloons</a></p><p>In the problem you should carefully get formula. The optimal solution put marbles by two in a row. And then put one marble upon others if it possible. The most difficulties were to deal with this last phase. </p><p>In comments to the post were given formulas how to put the last marble (exactly in the middle). And there was a good beautiful illustration, which describes the situation.</p><p><a href=\"/contest/342/problem/D\" title=\"Codeforces Round 199 (Div. 2)\">342D - Xenia and Dominoes</a></p><p>In the problem you can count number of correct puzzles or substract number of incorrect puzzles from number of all puzzles. In any case you should count DP, where the state is <span class=\"tex-span\">(<i>j</i>, <i>mask</i>)</span> — <span class=\"tex-span\"><i>j</i></span> — number of the last full column, <span class=\"tex-span\"><i>mask</i></span> — mask of the last column. This problem is equivalent to the well known problem about domino tiling or the problem about parquet.</p><p>To get the solution of the whole problem I did the following. I try to attach one domino to each of 4 directions, then paint all three cells in black and count the number of correct puzzles. But in this case you will count some solutions several number of times. So you need to use inclusion exclusion formula for these 4 directions.</p><p><a href=\"/contest/342/problem/E\" title=\"Codeforces Round 199 (Div. 2)\">342E - Xenia and Tree</a></p><p>The problem can be solved in different ways. The most easy idea is sqrt-optimization. Split all queries into <span class=\"tex-span\"><i>sqrt</i>(<i>m</i>)</span> blocks. Each block we will process separately. Before processing each block, we should calculate minimum distances from every node to the closest red node using bfs. To answer the query we should update this value by shortest distances to red nodes in current block.</p><p>The solution becomes simple. Every <span class=\"tex-span\"><i>sqrt</i>(<i>m</i>)</span> queries we make simple bfs and for every node <span class=\"tex-span\"><i>v</i></span> WE calculate value <span class=\"tex-span\"><i>d</i>[<i>v</i>]</span> — the shortest distance to some red node from node <span class=\"tex-span\"><i>v</i></span>. Then to answer the query of type 2 you should calculate <span class=\"tex-span\"><i>min</i>(<i>d</i>[<i>v</i>], <i>dist</i>(<i>v</i>, <i>u</i>))</span>, where <span class=\"tex-span\"><i>u</i></span> — every red node, which becomes red in current block of length <span class=\"tex-span\"><i>sqrt</i>(<i>m</i>)</span>.</p><p>Distance between two nodes <span class=\"tex-span\"><i>dist</i>(<i>u</i>, <i>v</i>)</span> can be got using preprocessing for lca.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/342\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 199 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-230-8855\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"230\",\n blogEntryId: \"8800\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=199\" class=\"tag notice\" style=\"text-decoration: none;\">199</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8855\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+38</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8855\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/HolkinPV\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/HolkinPV\">\n HolkinPV\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/07/2013 14:37\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8800#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8800#comments\">\n 43\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8871\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (38)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145322\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/10/2013 19:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145322\" href=\"?#comment-145322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain problem D in more detail, I am not able to understand anything from what is posted. </p><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145322\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145419\" commentParentId=\"145322\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Smit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/19252/avatar/d7815c7f59ae1a65.jpg'/> </a>\n <div><a href=\"/profile/Smit\" title=\"Master Smit\" class=\"rated-user user-orange\">Smit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/12/2013 02:41\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145419\" href=\"?#comment-145419\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145322\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145419\" revisionCount=\"5\" revision=\"5\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">5</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145419\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"19252\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145419\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Solution is simple. let me explain it with a examples:</p><p>suppose we have filled all the empty blocks from column 0....i-1 and on ith column we have filled some of the empty blocks which is stored using mask 0,1,...,7</p><p>suppose if mask is currently 0 and i=2, so configuration could be something like this.</p> <pre><code>AA.X.\nAA.0.\nAA.X.\n</code></pre><p>blocks with A are already filled.</p><p>now we have two options, we might use some vertical block or not:</p> <pre><code>1. if we use vertical block and put it in first 2 rows. new state ----> (i,3)\n2. if we use vertical block and put it in last 2 rows. new state ----> (i,6)\n3. if we choose not to use vertical block we have to use 3 horizontal one ----> (i+1,7)\n</code></pre><p>now we are almost ready with solution and need to check while putting block if that box was empty earlier and which we put block near 0, we need to note this also.</p><p>I think, you should be able to understand my code now.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145419 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145419 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145419\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145868\" commentParentId=\"145419\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 14:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145868\" href=\"?#comment-145868\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145419\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145868\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145868\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could you please post the link to your solution.</p><p>I got the algorithm but I am lacking clarity over some points like considering the state (i,3), How does one keep track of whether a single vertical block was placed or 2 horizontal blocks covering the squares were placed.</p><p>Anyways, thanks for your explanation.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145868 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145868 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145868\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145885\" commentParentId=\"145868\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Smit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/19252/avatar/d7815c7f59ae1a65.jpg'/> </a>\n <div><a href=\"/profile/Smit\" title=\"Master Smit\" class=\"rated-user user-orange\">Smit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 16:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145885\" href=\"?#comment-145885\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145868\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145885\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"19252\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145885\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>solution: <a href=\"//codeforces.com/contest/342/submission/4424666\">http://codeforces.com/contest/342/submission/4424666</a></p><p>it does not matter whether it was vertical block or 2 horizontal block. (i,3) tells that all the blocks in first i-1 columns are filled and in this column there is only last row left to be filled.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145885 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145885 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145885\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145656\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rhd\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78747/avatar/b4494f9b3e154714.jpg'/> </a>\n <div><a href=\"/profile/rhd\" title=\"Unrated, rhd\" class=\"rated-user user-black\">rhd</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2013 04:45\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145656\" href=\"?#comment-145656\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145656\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145656\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78747\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145656\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>.d.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145656 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145656 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145656\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145671\" commentParentId=\"145656\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Qubit01\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1399/avatar/c963814250395100.jpg'/> </a>\n <div><a href=\"/profile/Qubit01\" title=\"Expert Qubit01\" class=\"rated-user user-blue\">Qubit01</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2013 12:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145671\" href=\"?#comment-145671\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145656\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145671\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1399\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145671\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Assume that you have the distances from vertex with index <em>1</em> to every vertex <em>u</em> in a vector <em>d[]</em>.</p><p>Define <em>lca(x, y)</em> the lowest common ancestor for vertex <em>x</em> and <em>y</em>. You must find out the distance from <em>v</em> to <em>u</em>. </p><p>The result is <em>d[u] + d[v] — 2 * lca(u, v)</em> because you add twice the distance from vertex <em>1</em> to <em>lca(u, v)</em> (that's where the 2 roads intersects). You can draw a tree on a paper and and work with some examples, it will be clearer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145671 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145671 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145671\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146192\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lkjslkjdlk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34453/avatar/944f96e876fade4b.jpg'/> </a>\n <div><a href=\"/profile/lkjslkjdlk\" title=\"Specialist lkjslkjdlk\" class=\"rated-user user-cyan\">lkjslkjdlk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 14:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146192\" href=\"?#comment-146192\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146192\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34453\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146192\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could you please tell me the complexity of the Problem E?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146192 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146192 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146192\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146196\" commentParentId=\"146192\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lkjslkjdlk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34453/avatar/944f96e876fade4b.jpg'/> </a>\n <div><a href=\"/profile/lkjslkjdlk\" title=\"Specialist lkjslkjdlk\" class=\"rated-user user-cyan\">lkjslkjdlk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 16:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146196\" href=\"?#comment-146196\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146192\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146196\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34453\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146196\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here is my solution: <a href=\"//codeforces.com/contest/342/submission/4509629\">http://codeforces.com/contest/342/submission/4509629</a> The complexity seems to be O((n+m)*sqrt(m)). But it still gets TLE.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146196 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146196 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146196\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"458577\" commentParentId=\"146196\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mahagoni\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/567134/avatar/f60a9c806d357d9e.jpg'/> </a>\n <div><a href=\"/profile/Mahagoni\" title=\"Expert Mahagoni\" class=\"rated-user user-blue\">Mahagoni</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2018 00:21\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-458577\" href=\"?#comment-458577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146196\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"458577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"567134\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-458577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><em>O(n*sqrt(m)*log(n))</em></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-458577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-458577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-458577\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"673071\" commentParentId=\"146192\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/muzzaleeni\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/621091/avatar/e6a7f915e328dcd8.jpg'/> </a>\n <div><a href=\"/profile/muzzaleeni\" title=\"Pupil muzzaleeni\" class=\"rated-user user-green\">muzzaleeni</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/02/2020 11:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-673071\" href=\"?#comment-673071\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146192\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"673071\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"621091\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-673071\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>\\begin{equation}m \\cdot\\sqrt{m}\\cdot\\log_2{(n)}\\end{equation}</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-673071 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-673071 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-673071\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"937837\" commentParentId=\"673071\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Phantom_Performer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1746799/avatar/bc1dcacc56722125.jpg'/> </a>\n <div><a href=\"/profile/Phantom_Performer\" title=\"Master Phantom_Performer\" class=\"rated-user user-orange\">Phantom_Performer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/30/2022 17:45\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-937837\" href=\"?#comment-937837\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-673071\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"937837\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1746799\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-937837\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can precalculate the lca of nodes in Mlogn</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-937837 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-937837 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-937837\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"156861\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Harun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48372/avatar/15bf49d98279c433.jpg'/> </a>\n <div><a href=\"/profile/Harun\" title=\"Expert Harun\" class=\"rated-user user-blue\">Harun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/05/2014 22:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-156861\" href=\"?#comment-156861\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"156861\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48372\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-156861\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In E problem , there isn't any boundary case like chain. Then O(N*N) solution can get AC.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-156861 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-156861 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-156861\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"545136\" commentParentId=\"156861\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SevenDeadlySins\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/430874/avatar/b011182bef4f60f0.jpg'/> </a>\n <div><a href=\"/profile/SevenDeadlySins\" title=\"Pupil SevenDeadlySins\" class=\"rated-user user-green\">SevenDeadlySins</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2019 13:59\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-545136\" href=\"?#comment-545136\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-156861\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"545136\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"430874\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-545136\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>did u code in cpp?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-545136 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-545136 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-545136\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"545137\" commentParentId=\"545136\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Harun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48372/avatar/15bf49d98279c433.jpg'/> </a>\n <div><a href=\"/profile/Harun\" title=\"Expert Harun\" class=\"rated-user user-blue\">Harun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2019 14:04\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-545137\" href=\"?#comment-545137\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-545136\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"545137\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48372\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-545137\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don’t even remember what I had for dinner last night and you’re here asking me about a code I wrote 6 years ago. That’s like a lot of months :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-545137 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-545137 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-545137\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"545138\" commentParentId=\"545137\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SevenDeadlySins\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/430874/avatar/b011182bef4f60f0.jpg'/> </a>\n <div><a href=\"/profile/SevenDeadlySins\" title=\"Pupil SevenDeadlySins\" class=\"rated-user user-green\">SevenDeadlySins</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2019 14:09\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-545138\" href=\"?#comment-545138\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-545137\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"545138\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"430874\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-545138\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>That can be answered with what language u used to code with... But anyway you have a point... and I got the ans after stalking your profile... Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-545138 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-545138 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-545138\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"174599\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dtalamas24\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60129/avatar/200478a7b9850d4b.jpg'/> </a>\n <div><a href=\"/profile/dtalamas24\" title=\"Candidate Master dtalamas24\" class=\"rated-user user-violet\">dtalamas24</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2014 09:33\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-174599\" href=\"?#comment-174599\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"174599\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"174599\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60129\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-174599\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Any online solutions for problem E ? Or different solutions to E?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-174599 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-174599 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-174599\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176403\" commentParentId=\"174599\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kllp\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/100053/avatar/44882b58f6756412.jpg'/> </a>\n <div><a href=\"/profile/kllp\" title=\"Master kllp\" class=\"rated-user user-orange\">kllp</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/02/2014 23:38\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176403\" href=\"?#comment-176403\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-174599\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"176403\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"100053\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176403\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My solution uses Heavy-light decomposition and segment trees. Complexity is O(N log^2 N). <a href=\"//codeforces.com/contest/342/submission/6999318\">http://codeforces.com/contest/342/submission/6999318</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176403 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176403 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176403\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"181789\" commentParentId=\"176403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Harun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48372/avatar/15bf49d98279c433.jpg'/> </a>\n <div><a href=\"/profile/Harun\" title=\"Expert Harun\" class=\"rated-user user-blue\">Harun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/09/2014 17:53\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-181789\" href=\"?#comment-181789\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"181789\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48372\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-181789\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could you explain your idea ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-181789 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-181789 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-181789\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"252934\" commentParentId=\"176403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/manmodeashish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/manmodeashish\" title=\"Specialist manmodeashish\" class=\"rated-user user-cyan\">manmodeashish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/28/2015 12:33\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-252934\" href=\"?#comment-252934\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"252934\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"226988\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-252934\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>very good. It was really helpful. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-252934 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-252934 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-252934\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"442050\" commentParentId=\"176403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cai_lw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/325977/avatar/202b61935928944.jpg'/> </a>\n <div><a href=\"/profile/cai_lw\" title=\"International Master cai_lw\" class=\"rated-user user-orange\">cai_lw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/02/2018 17:36\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-442050\" href=\"?#comment-442050\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"442050\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"325977\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-442050\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We can achieve O(NlogN) if we store each "heavy chains" in separate segment trees. For each operation, all queries and updates, except the beginning one, are on the whole chain, and only takes O(1). Therefore, each operation takes O(logN)*O(1)+O(1)*O(logN)=O(logN)</p><p><a href=\"//codeforces.com/contest/342/submission/39871066\">My solution</a> (it doesn't run faster in practice though)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-442050 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-442050 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-442050\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"213929\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mindbeats\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/56717/avatar/bcddf2e5600931f3.jpg'/> </a>\n <div><a href=\"/profile/mindbeats\" title=\"Expert mindbeats\" class=\"rated-user user-blue\">mindbeats</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2015 00:14\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-213929\" href=\"?#comment-213929\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"213929\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"56717\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-213929\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in problem E, the complexity is O(N * sqrtN * logN).... logN because of the LCA part it doesn't pass the time</p><p>how did you handle this !!?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-213929 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-213929 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-213929\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"937838\" commentParentId=\"213929\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Phantom_Performer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1746799/avatar/bc1dcacc56722125.jpg'/> </a>\n <div><a href=\"/profile/Phantom_Performer\" title=\"Master Phantom_Performer\" class=\"rated-user user-orange\">Phantom_Performer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/30/2022 17:45\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-937838\" href=\"?#comment-937838\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-213929\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"937838\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1746799\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-937838\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can precalculate the lca of nodes in Mlogn</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-937838 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-937838 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-937838\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"937911\" commentParentId=\"937838\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mindbeats\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/56717/avatar/bcddf2e5600931f3.jpg'/> </a>\n <div><a href=\"/profile/mindbeats\" title=\"Expert mindbeats\" class=\"rated-user user-blue\">mindbeats</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/31/2022 05:01\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-937911\" href=\"?#comment-937911\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-937838\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"937911\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"56717\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-937911\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>oh 7 years to get an answer...that was really too fast! :D </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-937911 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-937911 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-937911\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"316277\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2016 18:20\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-316277\" href=\"?#comment-316277\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"316277\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"316277\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-316277\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Deleted</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-316277 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-316277 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-316277\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"335462\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/....\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/....\" title=\"Expert ....\" class=\"rated-user user-blue\">....</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/04/2017 21:36\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-335462\" href=\"?#comment-335462\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"335462\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"335462\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"490997\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-335462\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem <a href=\"/contest/342/problem/E\" title=\"Codeforces Round 199 (Div. 2)\">342E - Xenia and Tree</a>, I came across a centroid decomposition solution <a href=\"/contest/342/submission/23224047\" title=\"Submission 23224047 by raiden_11\">23224047</a>. I have gone through the solution, but I am not able to convince myself about the correctness of the algorithm and the reason as to why query method is correct(or works). Please help!</p><p>PS: <a class=\"rated-user user-violet\" href=\"/profile/HolkinPV\" title=\"Candidate Master HolkinPV\">HolkinPV</a>, can you please help?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-335462 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-335462 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-335462\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"528302\" commentParentId=\"335462\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/VLADO\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/630234/avatar/e6872ed793f74338.jpg'/> </a>\n <div><a href=\"/profile/VLADO\" title=\"Expert VLADO\" class=\"rated-user user-blue\">VLADO</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/19/2019 15:37\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-528302\" href=\"?#comment-528302\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-335462\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"528302\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"630234\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-528302\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm a bit late but the solution is explained <a href=\"https://threads-iiith.quora.com/Centroid-Decomposition-of-a-Tree\">here</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-528302 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-528302 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-528302\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"370331\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/S.Jindal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/508955/avatar/43cfebadfb0dea2c.jpg'/> </a>\n <div><a href=\"/profile/S.Jindal\" title=\"Candidate Master S.Jindal\" class=\"rated-user user-violet\">S.Jindal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/29/2017 07:28\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-370331\" href=\"?#comment-370331\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"370331\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"508955\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-370331\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve Div1,C if we have to return the maximum distance to any red node instead of min distance...?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-370331 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-370331 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-370331\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371401\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nitesh_gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/454345/avatar/88dd212e02074fb0.jpg'/> </a>\n <div><a href=\"/profile/nitesh_gupta\" title=\"Master nitesh_gupta\" class=\"rated-user user-orange\">nitesh_gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/03/2017 11:52\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371401\" href=\"?#comment-371401\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"371401\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"371401\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"454345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371401\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"Distance between two nodes dist(u, v) can be got using preprocessing for lca." - Xenia and Tree</p><p>Can anyone explain me how to do it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371401 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371401 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371401\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371545\" commentParentId=\"371401\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MasT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/451310/avatar/10587ffa9ae01331.jpg'/> </a>\n <div><a href=\"/profile/MasT\" title=\"Expert MasT\" class=\"rated-user user-blue\">MasT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2017 07:00\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371545\" href=\"?#comment-371545\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371401\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"371545\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"371545\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"451310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371545\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Notice that <code>dist(u, v) = dist(root, u) + dist(root, v) - 2 * dist(root, l)</code>, where l is the LCA of u and v</p><p>1) Use a DFS to find the distance from node 1 (the root) to every other node. Let <code>rootDist[n]</code> by the distance from node 1 to node n. The DFS should also find the parent of each node, and the depth of each node from the root. Let <code>parent[n]</code> be the parent of node n and <code>depth[n]</code> be the depth of node n.</p><p>Example DFS code:</p> <pre><code>//Let MAX be the number of maximum nodes\nvector<int> adj[MAX];\nint rootDist[MAX], parent[MAX], depth[MAX];\n\n// cur = Current traversing node\n// prev = Node traversed before this one\nint dfs(int cur, int prev){\n parent[cur] = prev;\n\n for(int child : adj[cur]){\n if(child != prev){\n depth[child] = depth[cur] + 1;\n rootDist[child] = rootDist[cur] + 1;\n // Note: In the case of an unweighted tree,\n // depth[n] == rootDist[n]\n\n dfs(child, cur);\n\n }\n }\n}\n\ndfs(1, -1);\n</code></pre><p>2) Build a sparse table. <code>sparse[u][i]</code> stores the 2**i-th parent of u, or <code>-1</code> if that parent doesn't exist. Note that <code>sparse[u][0] = parent[n]</code>. The sparse table can be built by:</p> <pre><code>// N = number of nodes as given in input\n// LN = ceil(log2(Max number of nodes))\n// Using 1-indexing for nodes\nint sparse[MAX][LN];\nmemset(sparse, -1, sizeof sparse);\n\nfor(int u = 1; u <= N; u++)\n sparse[u][0] = parent[u];\n\nfor(int i = 1; i < LN; i++)\n for(int u = 1; u <= N; u++)\n //if the node has a 2**(i - 1)th parent\n if(sparse[u][i - 1] != -1)\n // the 2**i-th parent of u is equal to\n // the 2**(i - 1)th parent of 2**(i - 1)th parent of u\n sparse[u][i] = sparse [ sparse[u][i - 1] ] [i - 1];\n</code></pre><p>3) To query the lca of u and v, we do the following steps:</p> <ol> <li>If u has a smaller depth than v, swap them</li> <li>Find the ancestor of u with the same depth of v</li> <li>If u and v are the same node, return it</li> <li>Find the highest (least depth) ancestor of u and v (let's call them u' and v') such that u' is not v'</li> <li>Return the parent of u' (which is equal to the parent of v')</li> </ol><p>Here is the code for the query:</p> <pre><code>int lca(int u, int v){\n if(depth[u] < depth[v])\n swap(u, v);\n\n // We use sparse table so we jump 2**i parents each time\n // Taking only log time\n for(int i = LN - 1; i >= 0; i--)\n // If the 2**i-th parent of u isn't higher than v\n if(depth[ sparse[u][i] ] >= depth[v])\n // Go up 2**i parents\n u = sparse[u][i];\n\n // At this point, depth[u] == depth[v]\n // If they happen to be the same node, that is the LCA\n if(u == v)\n return u;\n\n for(int i = LN - 1; i >= 0; i--){\n // If their ancestors aren't the same\n if(sparse[u][i] != sparse[v][i]){\n // Go up to their ancestor\n u = sparse[u][i];\n v = sparse[v][i];\n }\n }\n\n // At this point, they're at the highest ancestor\n // such that they're not the same, so one parent above\n // must be their LCA\n\n // 2**0 = 1, return first parent of u\n return sparse[u][0];\n // this is also equal to sparse[v][0]\n}\n</code></pre><p>And finally, to put it all together, to query distance</p> <pre><code>int dist(int u, int v){\n int l = lca(u, v);\n return rootDist[u] + rootDist[v] - 2 * rootDist[l];\n}\n</code></pre><p>Building the LCA sparse table takes <code>O(n log n)</code> time while querying takes <code>O(log n)</code> time</p><p>(I wrote this from memory; please tell me if there are any mistakes or if any part is confusing)</p><p><a href=\"https://www.topcoder.com/community/data-science/data-science-tutorials/range-minimum-query-and-lowest-common-ancestor/\">Source/Additional reading</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371545 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371545 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371545\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371617\" commentParentId=\"371545\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nitesh_gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/454345/avatar/88dd212e02074fb0.jpg'/> </a>\n <div><a href=\"/profile/nitesh_gupta\" title=\"Master nitesh_gupta\" class=\"rated-user user-orange\">nitesh_gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2017 20:32\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371617\" href=\"?#comment-371617\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371545\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"371617\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"454345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371617\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for your help. You explained very well.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371617 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371617 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371617\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"425765\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sonupmandal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/356694/avatar/a3df14f7c5265075.jpg'/> </a>\n <div><a href=\"/profile/sonupmandal\" title=\"Pupil sonupmandal\" class=\"rated-user user-green\">sonupmandal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/18/2018 07:38\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-425765\" href=\"?#comment-425765\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"425765\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"356694\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-425765\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to do this - Calculate minimum distances from every node to the closest red node using bfs.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-425765 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-425765 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-425765\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"432106\" commentParentId=\"425765\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kayak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/700181/avatar/ec3f04c38ba70bde.jpg'/> </a>\n <div><a href=\"/profile/kayak\" title=\"Expert kayak\" class=\"rated-user user-blue\">kayak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2018 18:49\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-432106\" href=\"?#comment-432106\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-425765\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"432106\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"432106\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"700181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-432106\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Store all nodes which are currently red in a vector redlist. Create an queue bfslist for bfs, and create a array <code>dist[v] = Distance from v to the nearest red node, 0 if v is itself red</code> and initialize an empty queue. Now for all red vertices <span class=\"tex-span\"><i>v</i></span>, let <code>dist[v] = 0</code> and push all the neighbours <span class=\"tex-span\"><i>u</i></span> of the red vertices which are not red into this queue, and for all such <span class=\"tex-span\"><i>u</i></span>, let <code>dist[u] = 1, isdiscovered[u] = 1</code>. Now it's just regular bfs: while the queue is nonempty, pop the first element <code>w</code> from the queue, and add all the neighbours <code>y</code> of <code>w</code> not already discovered to the queue, and let <code>dist[y] = dist[w] +1, isdiscovered[y] = 1</code>. Here's a code implementing it:</p> <pre><code>void bfs(){\n std::queue<int> bfslist;\n int isdisc[N] = {0};\n for (int i = 0; i < red.size(); i +=1){\n int a = red[i];\n reddist[a] = 0;\n isdisc[i] = 1;\n for (int j = 0; j < adjlist[a].size(); j +=1){\n int b = adjlist[a][j];\n if ((isred[b] == 1) && (isdisc[b] == 0)){\n bfslist.push(b);\n reddist[b] = 1;\n isdisc[b] = 1;\n }\n }\n }\n while (!bfslist.empty()){\n int a = bfslist.front();\n bfslist.pop();\n for (int i = 0; i < adjlist[a].size(); i +=1){\n int b = adjlist[a][i];\n if ((isred[b] ==1) && (isdisc[b] == 0)){\n bfslist.push(b);\n reddist[b] = reddist[a]+1;\n isdisc[b] = 1;\n }\n }\n }\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-432106 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-432106 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-432106\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"446034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arjitkansal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/542324/avatar/cb05cf6d94faff9c.jpg'/> </a>\n <div><a href=\"/profile/arjitkansal\" title=\"Master arjitkansal\" class=\"rated-user user-orange\">arjitkansal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/18/2018 09:51\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-446034\" href=\"?#comment-446034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"446034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"542324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-446034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, can anyone please help me debug this code for Problem E. </p><p><a href=\"https://codeforces.com/contest/342/submission/39819558\">https://codeforces.com/contest/342/submission/39819558</a></p><p>It has been days and I've not been able to find the error.</p><p>I used 'Centroid Decomposition'.</p><p>Thanks in Advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-446034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-446034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-446034\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"566831\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ac_97\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1211001/avatar/6e08c927b196de27.jpg'/> </a>\n <div><a href=\"/profile/ac_97\" title=\"Specialist ac_97\" class=\"rated-user user-cyan\">ac_97</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/24/2019 00:32\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-566831\" href=\"?#comment-566831\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"566831\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1211001\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-566831\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem Div2 E, can someone share the code implementing the sqrt optimization trick. Are there any resources for this technique ? In what all cases can this technique be applied ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-566831 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-566831 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-566831\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"598414\" commentParentId=\"566831\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Skeef79\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631759/avatar/3033511aaec49179.jpg'/> </a>\n <div><a href=\"/profile/Skeef79\" title=\"Candidate Master Skeef79\" class=\"rated-user user-violet\">Skeef79</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/06/2020 13:06\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-598414\" href=\"?#comment-598414\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-566831\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"598414\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"631759\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-598414\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://pastebin.com/cCYBLvjs\">https://pastebin.com/cCYBLvjs</a></p><p><a href=\"https://codeforces.com/contest/342/submission/75643716\">https://codeforces.com/contest/342/submission/75643716</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-598414 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-598414 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-598414\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"584071\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mooncrater\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/656776/avatar/d19b34b1e226e4ad.jpg'/> </a>\n <div><a href=\"/profile/Mooncrater\" title=\"Specialist Mooncrater\" class=\"rated-user user-cyan\">Mooncrater</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/26/2020 20:31\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-584071\" href=\"?#comment-584071\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"584071\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"656776\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-584071\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div2 C, what comments?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-584071 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-584071 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-584071\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"913528\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mynameisminh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/mynameisminh\" title=\"Newbie mynameisminh\" class=\"rated-user user-gray\">mynameisminh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2022 19:24\">17 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-913528\" href=\"?#comment-913528\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"913528\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2253580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-913528\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can somebody help me with problems 342E. Here's my source code: <a href=\"https://codeforces.com/problemset/submission/342/157723527\">https://codeforces.com/problemset/submission/342/157723527</a></p><p>I still don't know why I got TLE. Thanks so much!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-913528 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-913528 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-913528\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"924618\" commentParentId=\"913528\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lite_27\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2584952/avatar/d7812158a0f2af9b.jpg'/> </a>\n <div><a href=\"/profile/lite_27\" title=\"Specialist lite_27\" class=\"rated-user user-cyan\">lite_27</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2022 23:07\">16 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-924618\" href=\"?#comment-924618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-913528\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"924618\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"924618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2584952\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-924618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-924618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-924618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-924618\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8871\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8871 = true;\r\nvar lastPreviewContent8871 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8871] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8871] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8855\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8855, _tta: Codeforces.tta(), topicRevisionId: 31374, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8855\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8855, _tta: Codeforces.tta(), topicRevisionId: 31374, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:21</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'81287486695d9d99',t:'MTY5NjcwNTk0MS43NDgwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1733,"cells":{"problem_id":{"kind":"string","value":"342B"},"contest":{"kind":"string","value":"342"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Xenia and Spies"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Xenia and Spies</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Xenia the vigorous detective faced <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(<i>n</i> ≥ 2)</span> foreign spies lined up in a row. We'll consider the spies numbered from 1 to <span class=\"tex-span\"><i>n</i></span> from left to right. </p><p>Spy <span class=\"tex-span\"><i>s</i></span> has an important note. He has to pass the note to spy <span class=\"tex-span\"><i>f</i></span>. Xenia interrogates the spies in several steps. During one step the spy keeping the important note can pass the note to one of his neighbours in the row. In other words, if this spy's number is <span class=\"tex-span\"><i>x</i></span>, he can pass the note to another spy, either <span class=\"tex-span\"><i>x</i> - 1</span> or <span class=\"tex-span\"><i>x</i> + 1</span> (if <span class=\"tex-span\"><i>x</i> = 1</span> or <span class=\"tex-span\"><i>x</i> = <i>n</i></span>, then the spy has only one neighbour). Also during a step the spy can keep a note and not pass it to anyone.</p><p>But nothing is that easy. During <span class=\"tex-span\"><i>m</i></span> steps Xenia watches some spies attentively. Specifically, during step <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> (steps are numbered from 1) Xenia watches spies numbers <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>l</i><sub class=\"lower-index\"><i>i</i></sub> + 1, <i>l</i><sub class=\"lower-index\"><i>i</i></sub> + 2, ..., <i>r</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>r</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>)</span>. Of course, if during some step a spy is watched, he can't do anything: neither give the note nor take it from some other spy. Otherwise, Xenia reveals the spies' cunning plot. Nevertheless, if the spy at the current step keeps the note, Xenia sees nothing suspicious even if she watches him.</p><p>You've got <span class=\"tex-span\"><i>s</i></span> and <span class=\"tex-span\"><i>f</i></span>. Also, you have the steps during which Xenia watches spies and which spies she is going to watch during each step. Find the best way the spies should act in order to pass the note from spy <span class=\"tex-span\"><i>s</i></span> to spy <span class=\"tex-span\"><i>f</i></span> as quickly as possible (in the minimum number of steps).</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains four integers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>m</i></span>, <span class=\"tex-span\"><i>s</i></span> and <span class=\"tex-span\"><i>f</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i>, <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup>; 1 ≤ <i>s</i>, <i>f</i> ≤ <i>n</i>; <i>s</i> ≠ <i>f</i>; <i>n</i> ≥ 2)</span>. Each of the following <span class=\"tex-span\"><i>m</i></span> lines contains three integers <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub>, <i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>t</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>, 1 ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>r</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>)</span>. It is guaranteed that <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\">1</sub> < <i>t</i><sub class=\"lower-index\">2</sub> < <i>t</i><sub class=\"lower-index\">3</sub> < ... < <i>t</i><sub class=\"lower-index\"><i>m</i></sub></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print <span class=\"tex-span\"><i>k</i></span> characters in a line: the <span class=\"tex-span\"><i>i</i></span>-th character in the line must represent the spies' actions on step <span class=\"tex-span\"><i>i</i></span>. If on step <span class=\"tex-span\"><i>i</i></span> the spy with the note must pass the note to the spy with a lesser number, the <span class=\"tex-span\"><i>i</i></span>-th character should equal \"<span class=\"tex-font-style-tt\">L</span>\". If on step <span class=\"tex-span\"><i>i</i></span> the spy with the note must pass it to the spy with a larger number, the <span class=\"tex-span\"><i>i</i></span>-th character must equal \"<span class=\"tex-font-style-tt\">R</span>\". If the spy must keep the note at the <span class=\"tex-span\"><i>i</i></span>-th step, the <span class=\"tex-span\"><i>i</i></span>-th character must equal \"<span class=\"tex-font-style-tt\">X</span>\".</p><p>As a result of applying the printed sequence of actions spy <span class=\"tex-span\"><i>s</i></span> must pass the note to spy <span class=\"tex-span\"><i>f</i></span>. The number of printed characters <span class=\"tex-span\"><i>k</i></span> must be as small as possible. Xenia must not catch the spies passing the note.</p><p>If there are miltiple optimal solutions, you can print any of them. It is guaranteed that the answer exists.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 5 1 3<br/>1 1 2<br/>2 2 3<br/>3 3 3<br/>4 1 1<br/>10 1 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>XXRR<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"1fac12d0406f9fc6680ceb4fd3fe4c37\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"91a1e137bf92bd9ed30f9398e9597722ab5e17d3\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='1fac12d0406f9fc6680ceb4fd3fe4c37'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F342%2Fproblem%2FB%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='1fac12d0406f9fc6680ceb4fd3fe4c37'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/342\">Codeforces Round 199 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='1fac12d0406f9fc6680ceb4fd3fe4c37'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/342/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Brute force\">\r\n brute force\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1500\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='1fac12d0406f9fc6680ceb4fd3fe4c37'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3439\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='1fac12d0406f9fc6680ceb4fd3fe4c37'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3439\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8795\" title=\"Codeforces Round #199 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1837:1838\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/8800\" title=\"Tutorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1840\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/342\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/342/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/342/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/342/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/342/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/342/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/342/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/342/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_2fcc29a753beadd3ae375532d66b65c361084b4a\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Xenia and Spies</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Xenia the vigorous detective faced <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(<i>n</i> ≥ 2)</span> foreign spies lined up in a row. We'll consider the spies numbered from 1 to <span class=\"tex-span\"><i>n</i></span> from left to right. </p><p>Spy <span class=\"tex-span\"><i>s</i></span> has an important note. He has to pass the note to spy <span class=\"tex-span\"><i>f</i></span>. Xenia interrogates the spies in several steps. During one step the spy keeping the important note can pass the note to one of his neighbours in the row. In other words, if this spy's number is <span class=\"tex-span\"><i>x</i></span>, he can pass the note to another spy, either <span class=\"tex-span\"><i>x</i> - 1</span> or <span class=\"tex-span\"><i>x</i> + 1</span> (if <span class=\"tex-span\"><i>x</i> = 1</span> or <span class=\"tex-span\"><i>x</i> = <i>n</i></span>, then the spy has only one neighbour). Also during a step the spy can keep a note and not pass it to anyone.</p><p>But nothing is that easy. During <span class=\"tex-span\"><i>m</i></span> steps Xenia watches some spies attentively. Specifically, during step <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> (steps are numbered from 1) Xenia watches spies numbers <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>l</i><sub class=\"lower-index\"><i>i</i></sub> + 1, <i>l</i><sub class=\"lower-index\"><i>i</i></sub> + 2, ..., <i>r</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>r</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>)</span>. Of course, if during some step a spy is watched, he can't do anything: neither give the note nor take it from some other spy. Otherwise, Xenia reveals the spies' cunning plot. Nevertheless, if the spy at the current step keeps the note, Xenia sees nothing suspicious even if she watches him.</p><p>You've got <span class=\"tex-span\"><i>s</i></span> and <span class=\"tex-span\"><i>f</i></span>. Also, you have the steps during which Xenia watches spies and which spies she is going to watch during each step. Find the best way the spies should act in order to pass the note from spy <span class=\"tex-span\"><i>s</i></span> to spy <span class=\"tex-span\"><i>f</i></span> as quickly as possible (in the minimum number of steps).</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains four integers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>m</i></span>, <span class=\"tex-span\"><i>s</i></span> and <span class=\"tex-span\"><i>f</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i>, <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup>; 1 ≤ <i>s</i>, <i>f</i> ≤ <i>n</i>; <i>s</i> ≠ <i>f</i>; <i>n</i> ≥ 2)</span>. Each of the following <span class=\"tex-span\"><i>m</i></span> lines contains three integers <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub>, <i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>t</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>, 1 ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>r</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>)</span>. It is guaranteed that <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\">1</sub> < <i>t</i><sub class=\"lower-index\">2</sub> < <i>t</i><sub class=\"lower-index\">3</sub> < ... < <i>t</i><sub class=\"lower-index\"><i>m</i></sub></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print <span class=\"tex-span\"><i>k</i></span> characters in a line: the <span class=\"tex-span\"><i>i</i></span>-th character in the line must represent the spies' actions on step <span class=\"tex-span\"><i>i</i></span>. If on step <span class=\"tex-span\"><i>i</i></span> the spy with the note must pass the note to the spy with a lesser number, the <span class=\"tex-span\"><i>i</i></span>-th character should equal "<span class=\"tex-font-style-tt\">L</span>". If on step <span class=\"tex-span\"><i>i</i></span> the spy with the note must pass it to the spy with a larger number, the <span class=\"tex-span\"><i>i</i></span>-th character must equal "<span class=\"tex-font-style-tt\">R</span>". If the spy must keep the note at the <span class=\"tex-span\"><i>i</i></span>-th step, the <span class=\"tex-span\"><i>i</i></span>-th character must equal "<span class=\"tex-font-style-tt\">X</span>".</p><p>As a result of applying the printed sequence of actions spy <span class=\"tex-span\"><i>s</i></span> must pass the note to spy <span class=\"tex-span\"><i>f</i></span>. The number of printed characters <span class=\"tex-span\"><i>k</i></span> must be as small as possible. Xenia must not catch the spies passing the note.</p><p>If there are miltiple optimal solutions, you can print any of them. It is guaranteed that the answer exists.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 5 1 3<br />1 1 2<br />2 2 3<br />3 3 3<br />4 1 1<br />10 1 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>XXRR<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:28</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bd4ebb931672',t:'MTY5NjY0NjAwOC4yMTIwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Brute force\", \"Greedy algorithms\", \"Implementation problems, programming technics, simulation\"]"},"short_tags":{"kind":"string","value":"[\"brute force\", \"greedy\", \"implementation\", \"*1500\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8800"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"779401b049eaea220649756fcc29cd29\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #199 (Div. 2) Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #199 (Div. 2) Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='779401b049eaea220649756fcc29cd29'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8800\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='779401b049eaea220649756fcc29cd29'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:41</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:41</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='779401b049eaea220649756fcc29cd29'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/HolkinPV\">HolkinPV</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/HolkinPV\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/HolkinPV\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/HolkinPV\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/HolkinPV\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/HolkinPV\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/HolkinPV\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/HolkinPV\" style=\"text-decoration:none;color:black !important;\">HolkinPV's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8855\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8800\"> <p>Codeforces Round #199 (Div. 2) Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/HolkinPV\" title=\"Candidate Master HolkinPV\" class=\"rated-user user-violet\">HolkinPV</a>,\r\n <span class=\"format-humantime\" title=\"Sep/07/2013 14:37\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/342/problem/A\" title=\"Codeforces Round 199 (Div. 2)\">342A - Xenia and Divisors</a></p><p>In this problem you should guess that exists only three valid groups of three </p><p>1) 1, 2, 4 </p><p>2) 1, 2, 6 </p><p>3) 1, 3, 6 </p><p>(You can see that integers 5 and 7 are bad).</p><p>So, we will greedy take these groups of three. If some integers will be not used, the answer is -1. In other case, print found answer.</p><p><a href=\"/contest/342/problem/B\" title=\"Codeforces Round 199 (Div. 2)\">342B - Xenia and Spies</a></p><p>The problem is solved by greedy algorithm. We will pass the note only in correct direction. Also, if we can pass the note at the current moment of time, we do it. In other case, we will hold it and don't give it to neighbors (we can make this action at any moment of time). Obviously this algorithm is correct. You should only implement it carefully.</p><p><a href=\"/contest/342/problem/C\" title=\"Codeforces Round 199 (Div. 2)\">342C - Cupboard and Balloons</a></p><p>In the problem you should carefully get formula. The optimal solution put marbles by two in a row. And then put one marble upon others if it possible. The most difficulties were to deal with this last phase. </p><p>In comments to the post were given formulas how to put the last marble (exactly in the middle). And there was a good beautiful illustration, which describes the situation.</p><p><a href=\"/contest/342/problem/D\" title=\"Codeforces Round 199 (Div. 2)\">342D - Xenia and Dominoes</a></p><p>In the problem you can count number of correct puzzles or substract number of incorrect puzzles from number of all puzzles. In any case you should count DP, where the state is <span class=\"tex-span\">(<i>j</i>, <i>mask</i>)</span> — <span class=\"tex-span\"><i>j</i></span> — number of the last full column, <span class=\"tex-span\"><i>mask</i></span> — mask of the last column. This problem is equivalent to the well known problem about domino tiling or the problem about parquet.</p><p>To get the solution of the whole problem I did the following. I try to attach one domino to each of 4 directions, then paint all three cells in black and count the number of correct puzzles. But in this case you will count some solutions several number of times. So you need to use inclusion exclusion formula for these 4 directions.</p><p><a href=\"/contest/342/problem/E\" title=\"Codeforces Round 199 (Div. 2)\">342E - Xenia and Tree</a></p><p>The problem can be solved in different ways. The most easy idea is sqrt-optimization. Split all queries into <span class=\"tex-span\"><i>sqrt</i>(<i>m</i>)</span> blocks. Each block we will process separately. Before processing each block, we should calculate minimum distances from every node to the closest red node using bfs. To answer the query we should update this value by shortest distances to red nodes in current block.</p><p>The solution becomes simple. Every <span class=\"tex-span\"><i>sqrt</i>(<i>m</i>)</span> queries we make simple bfs and for every node <span class=\"tex-span\"><i>v</i></span> WE calculate value <span class=\"tex-span\"><i>d</i>[<i>v</i>]</span> — the shortest distance to some red node from node <span class=\"tex-span\"><i>v</i></span>. Then to answer the query of type 2 you should calculate <span class=\"tex-span\"><i>min</i>(<i>d</i>[<i>v</i>], <i>dist</i>(<i>v</i>, <i>u</i>))</span>, where <span class=\"tex-span\"><i>u</i></span> — every red node, which becomes red in current block of length <span class=\"tex-span\"><i>sqrt</i>(<i>m</i>)</span>.</p><p>Distance between two nodes <span class=\"tex-span\"><i>dist</i>(<i>u</i>, <i>v</i>)</span> can be got using preprocessing for lca.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/342\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 199 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-230-8855\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"230\",\n blogEntryId: \"8800\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=199\" class=\"tag notice\" style=\"text-decoration: none;\">199</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8855\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+38</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8855\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/HolkinPV\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/HolkinPV\">\n HolkinPV\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/07/2013 14:37\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8800#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8800#comments\">\n 43\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8871\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (38)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145322\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/10/2013 19:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145322\" href=\"?#comment-145322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain problem D in more detail, I am not able to understand anything from what is posted. </p><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145322\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145419\" commentParentId=\"145322\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Smit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/19252/avatar/d7815c7f59ae1a65.jpg'/> </a>\n <div><a href=\"/profile/Smit\" title=\"Master Smit\" class=\"rated-user user-orange\">Smit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/12/2013 02:41\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145419\" href=\"?#comment-145419\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145322\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145419\" revisionCount=\"5\" revision=\"5\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">5</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145419\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"19252\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145419\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Solution is simple. let me explain it with a examples:</p><p>suppose we have filled all the empty blocks from column 0....i-1 and on ith column we have filled some of the empty blocks which is stored using mask 0,1,...,7</p><p>suppose if mask is currently 0 and i=2, so configuration could be something like this.</p> <pre><code>AA.X.\nAA.0.\nAA.X.\n</code></pre><p>blocks with A are already filled.</p><p>now we have two options, we might use some vertical block or not:</p> <pre><code>1. if we use vertical block and put it in first 2 rows. new state ----> (i,3)\n2. if we use vertical block and put it in last 2 rows. new state ----> (i,6)\n3. if we choose not to use vertical block we have to use 3 horizontal one ----> (i+1,7)\n</code></pre><p>now we are almost ready with solution and need to check while putting block if that box was empty earlier and which we put block near 0, we need to note this also.</p><p>I think, you should be able to understand my code now.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145419 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145419 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145419\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145868\" commentParentId=\"145419\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 14:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145868\" href=\"?#comment-145868\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145419\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145868\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145868\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could you please post the link to your solution.</p><p>I got the algorithm but I am lacking clarity over some points like considering the state (i,3), How does one keep track of whether a single vertical block was placed or 2 horizontal blocks covering the squares were placed.</p><p>Anyways, thanks for your explanation.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145868 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145868 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145868\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145885\" commentParentId=\"145868\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Smit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/19252/avatar/d7815c7f59ae1a65.jpg'/> </a>\n <div><a href=\"/profile/Smit\" title=\"Master Smit\" class=\"rated-user user-orange\">Smit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 16:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145885\" href=\"?#comment-145885\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145868\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145885\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"19252\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145885\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>solution: <a href=\"//codeforces.com/contest/342/submission/4424666\">http://codeforces.com/contest/342/submission/4424666</a></p><p>it does not matter whether it was vertical block or 2 horizontal block. (i,3) tells that all the blocks in first i-1 columns are filled and in this column there is only last row left to be filled.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145885 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145885 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145885\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145656\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rhd\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78747/avatar/b4494f9b3e154714.jpg'/> </a>\n <div><a href=\"/profile/rhd\" title=\"Unrated, rhd\" class=\"rated-user user-black\">rhd</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2013 04:45\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145656\" href=\"?#comment-145656\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145656\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145656\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78747\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145656\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>.d.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145656 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145656 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145656\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145671\" commentParentId=\"145656\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Qubit01\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1399/avatar/c963814250395100.jpg'/> </a>\n <div><a href=\"/profile/Qubit01\" title=\"Expert Qubit01\" class=\"rated-user user-blue\">Qubit01</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2013 12:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145671\" href=\"?#comment-145671\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145656\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145671\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1399\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145671\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Assume that you have the distances from vertex with index <em>1</em> to every vertex <em>u</em> in a vector <em>d[]</em>.</p><p>Define <em>lca(x, y)</em> the lowest common ancestor for vertex <em>x</em> and <em>y</em>. You must find out the distance from <em>v</em> to <em>u</em>. </p><p>The result is <em>d[u] + d[v] — 2 * lca(u, v)</em> because you add twice the distance from vertex <em>1</em> to <em>lca(u, v)</em> (that's where the 2 roads intersects). You can draw a tree on a paper and and work with some examples, it will be clearer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145671 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145671 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145671\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146192\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lkjslkjdlk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34453/avatar/944f96e876fade4b.jpg'/> </a>\n <div><a href=\"/profile/lkjslkjdlk\" title=\"Specialist lkjslkjdlk\" class=\"rated-user user-cyan\">lkjslkjdlk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 14:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146192\" href=\"?#comment-146192\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146192\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34453\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146192\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could you please tell me the complexity of the Problem E?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146192 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146192 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146192\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146196\" commentParentId=\"146192\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lkjslkjdlk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34453/avatar/944f96e876fade4b.jpg'/> </a>\n <div><a href=\"/profile/lkjslkjdlk\" title=\"Specialist lkjslkjdlk\" class=\"rated-user user-cyan\">lkjslkjdlk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 16:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146196\" href=\"?#comment-146196\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146192\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146196\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34453\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146196\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here is my solution: <a href=\"//codeforces.com/contest/342/submission/4509629\">http://codeforces.com/contest/342/submission/4509629</a> The complexity seems to be O((n+m)*sqrt(m)). But it still gets TLE.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146196 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146196 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146196\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"458577\" commentParentId=\"146196\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mahagoni\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/567134/avatar/f60a9c806d357d9e.jpg'/> </a>\n <div><a href=\"/profile/Mahagoni\" title=\"Expert Mahagoni\" class=\"rated-user user-blue\">Mahagoni</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2018 00:21\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-458577\" href=\"?#comment-458577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146196\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"458577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"567134\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-458577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><em>O(n*sqrt(m)*log(n))</em></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-458577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-458577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-458577\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"673071\" commentParentId=\"146192\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/muzzaleeni\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/621091/avatar/e6a7f915e328dcd8.jpg'/> </a>\n <div><a href=\"/profile/muzzaleeni\" title=\"Pupil muzzaleeni\" class=\"rated-user user-green\">muzzaleeni</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/02/2020 11:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-673071\" href=\"?#comment-673071\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146192\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"673071\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"621091\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-673071\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>\\begin{equation}m \\cdot\\sqrt{m}\\cdot\\log_2{(n)}\\end{equation}</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-673071 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-673071 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-673071\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"937837\" commentParentId=\"673071\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Phantom_Performer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1746799/avatar/bc1dcacc56722125.jpg'/> </a>\n <div><a href=\"/profile/Phantom_Performer\" title=\"Master Phantom_Performer\" class=\"rated-user user-orange\">Phantom_Performer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/30/2022 17:45\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-937837\" href=\"?#comment-937837\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-673071\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"937837\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1746799\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-937837\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can precalculate the lca of nodes in Mlogn</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-937837 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-937837 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-937837\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"156861\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Harun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48372/avatar/15bf49d98279c433.jpg'/> </a>\n <div><a href=\"/profile/Harun\" title=\"Expert Harun\" class=\"rated-user user-blue\">Harun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/05/2014 22:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-156861\" href=\"?#comment-156861\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"156861\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48372\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-156861\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In E problem , there isn't any boundary case like chain. Then O(N*N) solution can get AC.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-156861 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-156861 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-156861\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"545136\" commentParentId=\"156861\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SevenDeadlySins\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/430874/avatar/b011182bef4f60f0.jpg'/> </a>\n <div><a href=\"/profile/SevenDeadlySins\" title=\"Pupil SevenDeadlySins\" class=\"rated-user user-green\">SevenDeadlySins</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2019 13:59\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-545136\" href=\"?#comment-545136\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-156861\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"545136\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"430874\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-545136\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>did u code in cpp?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-545136 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-545136 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-545136\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"545137\" commentParentId=\"545136\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Harun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48372/avatar/15bf49d98279c433.jpg'/> </a>\n <div><a href=\"/profile/Harun\" title=\"Expert Harun\" class=\"rated-user user-blue\">Harun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2019 14:04\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-545137\" href=\"?#comment-545137\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-545136\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"545137\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48372\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-545137\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don’t even remember what I had for dinner last night and you’re here asking me about a code I wrote 6 years ago. That’s like a lot of months :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-545137 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-545137 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-545137\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"545138\" commentParentId=\"545137\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SevenDeadlySins\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/430874/avatar/b011182bef4f60f0.jpg'/> </a>\n <div><a href=\"/profile/SevenDeadlySins\" title=\"Pupil SevenDeadlySins\" class=\"rated-user user-green\">SevenDeadlySins</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2019 14:09\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-545138\" href=\"?#comment-545138\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-545137\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"545138\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"430874\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-545138\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>That can be answered with what language u used to code with... But anyway you have a point... and I got the ans after stalking your profile... Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-545138 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-545138 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-545138\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"174599\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dtalamas24\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60129/avatar/200478a7b9850d4b.jpg'/> </a>\n <div><a href=\"/profile/dtalamas24\" title=\"Candidate Master dtalamas24\" class=\"rated-user user-violet\">dtalamas24</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2014 09:33\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-174599\" href=\"?#comment-174599\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"174599\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"174599\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60129\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-174599\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Any online solutions for problem E ? Or different solutions to E?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-174599 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-174599 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-174599\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176403\" commentParentId=\"174599\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kllp\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/100053/avatar/44882b58f6756412.jpg'/> </a>\n <div><a href=\"/profile/kllp\" title=\"Master kllp\" class=\"rated-user user-orange\">kllp</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/02/2014 23:38\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176403\" href=\"?#comment-176403\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-174599\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"176403\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"100053\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176403\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My solution uses Heavy-light decomposition and segment trees. Complexity is O(N log^2 N). <a href=\"//codeforces.com/contest/342/submission/6999318\">http://codeforces.com/contest/342/submission/6999318</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176403 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176403 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176403\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"181789\" commentParentId=\"176403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Harun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48372/avatar/15bf49d98279c433.jpg'/> </a>\n <div><a href=\"/profile/Harun\" title=\"Expert Harun\" class=\"rated-user user-blue\">Harun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/09/2014 17:53\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-181789\" href=\"?#comment-181789\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"181789\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48372\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-181789\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could you explain your idea ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-181789 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-181789 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-181789\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"252934\" commentParentId=\"176403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/manmodeashish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/manmodeashish\" title=\"Specialist manmodeashish\" class=\"rated-user user-cyan\">manmodeashish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/28/2015 12:33\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-252934\" href=\"?#comment-252934\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"252934\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"226988\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-252934\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>very good. It was really helpful. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-252934 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-252934 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-252934\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"442050\" commentParentId=\"176403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cai_lw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/325977/avatar/202b61935928944.jpg'/> </a>\n <div><a href=\"/profile/cai_lw\" title=\"International Master cai_lw\" class=\"rated-user user-orange\">cai_lw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/02/2018 17:36\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-442050\" href=\"?#comment-442050\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"442050\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"325977\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-442050\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We can achieve O(NlogN) if we store each "heavy chains" in separate segment trees. For each operation, all queries and updates, except the beginning one, are on the whole chain, and only takes O(1). Therefore, each operation takes O(logN)*O(1)+O(1)*O(logN)=O(logN)</p><p><a href=\"//codeforces.com/contest/342/submission/39871066\">My solution</a> (it doesn't run faster in practice though)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-442050 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-442050 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-442050\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"213929\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mindbeats\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/56717/avatar/bcddf2e5600931f3.jpg'/> </a>\n <div><a href=\"/profile/mindbeats\" title=\"Expert mindbeats\" class=\"rated-user user-blue\">mindbeats</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2015 00:14\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-213929\" href=\"?#comment-213929\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"213929\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"56717\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-213929\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in problem E, the complexity is O(N * sqrtN * logN).... logN because of the LCA part it doesn't pass the time</p><p>how did you handle this !!?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-213929 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-213929 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-213929\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"937838\" commentParentId=\"213929\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Phantom_Performer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1746799/avatar/bc1dcacc56722125.jpg'/> </a>\n <div><a href=\"/profile/Phantom_Performer\" title=\"Master Phantom_Performer\" class=\"rated-user user-orange\">Phantom_Performer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/30/2022 17:45\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-937838\" href=\"?#comment-937838\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-213929\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"937838\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1746799\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-937838\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can precalculate the lca of nodes in Mlogn</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-937838 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-937838 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-937838\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"937911\" commentParentId=\"937838\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mindbeats\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/56717/avatar/bcddf2e5600931f3.jpg'/> </a>\n <div><a href=\"/profile/mindbeats\" title=\"Expert mindbeats\" class=\"rated-user user-blue\">mindbeats</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/31/2022 05:01\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-937911\" href=\"?#comment-937911\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-937838\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"937911\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"56717\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-937911\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>oh 7 years to get an answer...that was really too fast! :D </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-937911 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-937911 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-937911\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"316277\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2016 18:20\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-316277\" href=\"?#comment-316277\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"316277\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"316277\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-316277\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Deleted</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-316277 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-316277 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-316277\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"335462\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/....\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/....\" title=\"Expert ....\" class=\"rated-user user-blue\">....</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/04/2017 21:36\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-335462\" href=\"?#comment-335462\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"335462\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"335462\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"490997\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-335462\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem <a href=\"/contest/342/problem/E\" title=\"Codeforces Round 199 (Div. 2)\">342E - Xenia and Tree</a>, I came across a centroid decomposition solution <a href=\"/contest/342/submission/23224047\" title=\"Submission 23224047 by raiden_11\">23224047</a>. I have gone through the solution, but I am not able to convince myself about the correctness of the algorithm and the reason as to why query method is correct(or works). Please help!</p><p>PS: <a class=\"rated-user user-violet\" href=\"/profile/HolkinPV\" title=\"Candidate Master HolkinPV\">HolkinPV</a>, can you please help?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-335462 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-335462 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-335462\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"528302\" commentParentId=\"335462\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/VLADO\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/630234/avatar/e6872ed793f74338.jpg'/> </a>\n <div><a href=\"/profile/VLADO\" title=\"Expert VLADO\" class=\"rated-user user-blue\">VLADO</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/19/2019 15:37\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-528302\" href=\"?#comment-528302\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-335462\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"528302\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"630234\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-528302\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm a bit late but the solution is explained <a href=\"https://threads-iiith.quora.com/Centroid-Decomposition-of-a-Tree\">here</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-528302 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-528302 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-528302\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"370331\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/S.Jindal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/508955/avatar/43cfebadfb0dea2c.jpg'/> </a>\n <div><a href=\"/profile/S.Jindal\" title=\"Candidate Master S.Jindal\" class=\"rated-user user-violet\">S.Jindal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/29/2017 07:28\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-370331\" href=\"?#comment-370331\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"370331\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"508955\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-370331\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve Div1,C if we have to return the maximum distance to any red node instead of min distance...?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-370331 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-370331 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-370331\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371401\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nitesh_gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/454345/avatar/88dd212e02074fb0.jpg'/> </a>\n <div><a href=\"/profile/nitesh_gupta\" title=\"Master nitesh_gupta\" class=\"rated-user user-orange\">nitesh_gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/03/2017 11:52\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371401\" href=\"?#comment-371401\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"371401\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"371401\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"454345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371401\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"Distance between two nodes dist(u, v) can be got using preprocessing for lca." - Xenia and Tree</p><p>Can anyone explain me how to do it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371401 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371401 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371401\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371545\" commentParentId=\"371401\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MasT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/451310/avatar/10587ffa9ae01331.jpg'/> </a>\n <div><a href=\"/profile/MasT\" title=\"Expert MasT\" class=\"rated-user user-blue\">MasT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2017 07:00\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371545\" href=\"?#comment-371545\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371401\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"371545\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"371545\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"451310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371545\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Notice that <code>dist(u, v) = dist(root, u) + dist(root, v) - 2 * dist(root, l)</code>, where l is the LCA of u and v</p><p>1) Use a DFS to find the distance from node 1 (the root) to every other node. Let <code>rootDist[n]</code> by the distance from node 1 to node n. The DFS should also find the parent of each node, and the depth of each node from the root. Let <code>parent[n]</code> be the parent of node n and <code>depth[n]</code> be the depth of node n.</p><p>Example DFS code:</p> <pre><code>//Let MAX be the number of maximum nodes\nvector<int> adj[MAX];\nint rootDist[MAX], parent[MAX], depth[MAX];\n\n// cur = Current traversing node\n// prev = Node traversed before this one\nint dfs(int cur, int prev){\n parent[cur] = prev;\n\n for(int child : adj[cur]){\n if(child != prev){\n depth[child] = depth[cur] + 1;\n rootDist[child] = rootDist[cur] + 1;\n // Note: In the case of an unweighted tree,\n // depth[n] == rootDist[n]\n\n dfs(child, cur);\n\n }\n }\n}\n\ndfs(1, -1);\n</code></pre><p>2) Build a sparse table. <code>sparse[u][i]</code> stores the 2**i-th parent of u, or <code>-1</code> if that parent doesn't exist. Note that <code>sparse[u][0] = parent[n]</code>. The sparse table can be built by:</p> <pre><code>// N = number of nodes as given in input\n// LN = ceil(log2(Max number of nodes))\n// Using 1-indexing for nodes\nint sparse[MAX][LN];\nmemset(sparse, -1, sizeof sparse);\n\nfor(int u = 1; u <= N; u++)\n sparse[u][0] = parent[u];\n\nfor(int i = 1; i < LN; i++)\n for(int u = 1; u <= N; u++)\n //if the node has a 2**(i - 1)th parent\n if(sparse[u][i - 1] != -1)\n // the 2**i-th parent of u is equal to\n // the 2**(i - 1)th parent of 2**(i - 1)th parent of u\n sparse[u][i] = sparse [ sparse[u][i - 1] ] [i - 1];\n</code></pre><p>3) To query the lca of u and v, we do the following steps:</p> <ol> <li>If u has a smaller depth than v, swap them</li> <li>Find the ancestor of u with the same depth of v</li> <li>If u and v are the same node, return it</li> <li>Find the highest (least depth) ancestor of u and v (let's call them u' and v') such that u' is not v'</li> <li>Return the parent of u' (which is equal to the parent of v')</li> </ol><p>Here is the code for the query:</p> <pre><code>int lca(int u, int v){\n if(depth[u] < depth[v])\n swap(u, v);\n\n // We use sparse table so we jump 2**i parents each time\n // Taking only log time\n for(int i = LN - 1; i >= 0; i--)\n // If the 2**i-th parent of u isn't higher than v\n if(depth[ sparse[u][i] ] >= depth[v])\n // Go up 2**i parents\n u = sparse[u][i];\n\n // At this point, depth[u] == depth[v]\n // If they happen to be the same node, that is the LCA\n if(u == v)\n return u;\n\n for(int i = LN - 1; i >= 0; i--){\n // If their ancestors aren't the same\n if(sparse[u][i] != sparse[v][i]){\n // Go up to their ancestor\n u = sparse[u][i];\n v = sparse[v][i];\n }\n }\n\n // At this point, they're at the highest ancestor\n // such that they're not the same, so one parent above\n // must be their LCA\n\n // 2**0 = 1, return first parent of u\n return sparse[u][0];\n // this is also equal to sparse[v][0]\n}\n</code></pre><p>And finally, to put it all together, to query distance</p> <pre><code>int dist(int u, int v){\n int l = lca(u, v);\n return rootDist[u] + rootDist[v] - 2 * rootDist[l];\n}\n</code></pre><p>Building the LCA sparse table takes <code>O(n log n)</code> time while querying takes <code>O(log n)</code> time</p><p>(I wrote this from memory; please tell me if there are any mistakes or if any part is confusing)</p><p><a href=\"https://www.topcoder.com/community/data-science/data-science-tutorials/range-minimum-query-and-lowest-common-ancestor/\">Source/Additional reading</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371545 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371545 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371545\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371617\" commentParentId=\"371545\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nitesh_gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/454345/avatar/88dd212e02074fb0.jpg'/> </a>\n <div><a href=\"/profile/nitesh_gupta\" title=\"Master nitesh_gupta\" class=\"rated-user user-orange\">nitesh_gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2017 20:32\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371617\" href=\"?#comment-371617\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371545\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"371617\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"454345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371617\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for your help. You explained very well.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371617 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371617 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371617\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"425765\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sonupmandal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/356694/avatar/a3df14f7c5265075.jpg'/> </a>\n <div><a href=\"/profile/sonupmandal\" title=\"Pupil sonupmandal\" class=\"rated-user user-green\">sonupmandal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/18/2018 07:38\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-425765\" href=\"?#comment-425765\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"425765\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"356694\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-425765\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to do this - Calculate minimum distances from every node to the closest red node using bfs.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-425765 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-425765 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-425765\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"432106\" commentParentId=\"425765\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kayak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/700181/avatar/ec3f04c38ba70bde.jpg'/> </a>\n <div><a href=\"/profile/kayak\" title=\"Expert kayak\" class=\"rated-user user-blue\">kayak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2018 18:49\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-432106\" href=\"?#comment-432106\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-425765\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"432106\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"432106\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"700181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-432106\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Store all nodes which are currently red in a vector redlist. Create an queue bfslist for bfs, and create a array <code>dist[v] = Distance from v to the nearest red node, 0 if v is itself red</code> and initialize an empty queue. Now for all red vertices <span class=\"tex-span\"><i>v</i></span>, let <code>dist[v] = 0</code> and push all the neighbours <span class=\"tex-span\"><i>u</i></span> of the red vertices which are not red into this queue, and for all such <span class=\"tex-span\"><i>u</i></span>, let <code>dist[u] = 1, isdiscovered[u] = 1</code>. Now it's just regular bfs: while the queue is nonempty, pop the first element <code>w</code> from the queue, and add all the neighbours <code>y</code> of <code>w</code> not already discovered to the queue, and let <code>dist[y] = dist[w] +1, isdiscovered[y] = 1</code>. Here's a code implementing it:</p> <pre><code>void bfs(){\n std::queue<int> bfslist;\n int isdisc[N] = {0};\n for (int i = 0; i < red.size(); i +=1){\n int a = red[i];\n reddist[a] = 0;\n isdisc[i] = 1;\n for (int j = 0; j < adjlist[a].size(); j +=1){\n int b = adjlist[a][j];\n if ((isred[b] == 1) && (isdisc[b] == 0)){\n bfslist.push(b);\n reddist[b] = 1;\n isdisc[b] = 1;\n }\n }\n }\n while (!bfslist.empty()){\n int a = bfslist.front();\n bfslist.pop();\n for (int i = 0; i < adjlist[a].size(); i +=1){\n int b = adjlist[a][i];\n if ((isred[b] ==1) && (isdisc[b] == 0)){\n bfslist.push(b);\n reddist[b] = reddist[a]+1;\n isdisc[b] = 1;\n }\n }\n }\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-432106 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-432106 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-432106\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"446034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arjitkansal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/542324/avatar/cb05cf6d94faff9c.jpg'/> </a>\n <div><a href=\"/profile/arjitkansal\" title=\"Master arjitkansal\" class=\"rated-user user-orange\">arjitkansal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/18/2018 09:51\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-446034\" href=\"?#comment-446034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"446034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"542324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-446034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, can anyone please help me debug this code for Problem E. </p><p><a href=\"https://codeforces.com/contest/342/submission/39819558\">https://codeforces.com/contest/342/submission/39819558</a></p><p>It has been days and I've not been able to find the error.</p><p>I used 'Centroid Decomposition'.</p><p>Thanks in Advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-446034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-446034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-446034\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"566831\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ac_97\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1211001/avatar/6e08c927b196de27.jpg'/> </a>\n <div><a href=\"/profile/ac_97\" title=\"Specialist ac_97\" class=\"rated-user user-cyan\">ac_97</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/24/2019 00:32\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-566831\" href=\"?#comment-566831\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"566831\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1211001\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-566831\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem Div2 E, can someone share the code implementing the sqrt optimization trick. Are there any resources for this technique ? In what all cases can this technique be applied ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-566831 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-566831 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-566831\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"598414\" commentParentId=\"566831\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Skeef79\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631759/avatar/3033511aaec49179.jpg'/> </a>\n <div><a href=\"/profile/Skeef79\" title=\"Candidate Master Skeef79\" class=\"rated-user user-violet\">Skeef79</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/06/2020 13:06\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-598414\" href=\"?#comment-598414\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-566831\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"598414\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"631759\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-598414\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://pastebin.com/cCYBLvjs\">https://pastebin.com/cCYBLvjs</a></p><p><a href=\"https://codeforces.com/contest/342/submission/75643716\">https://codeforces.com/contest/342/submission/75643716</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-598414 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-598414 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-598414\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"584071\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mooncrater\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/656776/avatar/d19b34b1e226e4ad.jpg'/> </a>\n <div><a href=\"/profile/Mooncrater\" title=\"Specialist Mooncrater\" class=\"rated-user user-cyan\">Mooncrater</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/26/2020 20:31\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-584071\" href=\"?#comment-584071\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"584071\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"656776\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-584071\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div2 C, what comments?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-584071 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-584071 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-584071\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"913528\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mynameisminh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/mynameisminh\" title=\"Newbie mynameisminh\" class=\"rated-user user-gray\">mynameisminh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2022 19:24\">17 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-913528\" href=\"?#comment-913528\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"913528\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2253580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-913528\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can somebody help me with problems 342E. Here's my source code: <a href=\"https://codeforces.com/problemset/submission/342/157723527\">https://codeforces.com/problemset/submission/342/157723527</a></p><p>I still don't know why I got TLE. Thanks so much!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-913528 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-913528 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-913528\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"924618\" commentParentId=\"913528\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lite_27\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2584952/avatar/d7812158a0f2af9b.jpg'/> </a>\n <div><a href=\"/profile/lite_27\" title=\"Specialist lite_27\" class=\"rated-user user-cyan\">lite_27</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2022 23:07\">16 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-924618\" href=\"?#comment-924618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-913528\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"924618\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"924618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2584952\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-924618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-924618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-924618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-924618\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8871\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8871 = true;\r\nvar lastPreviewContent8871 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8871] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8871] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8855\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8855, _tta: Codeforces.tta(), topicRevisionId: 31374, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8855\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8855, _tta: Codeforces.tta(), topicRevisionId: 31374, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:21</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'81287486695d9d99',t:'MTY5NjcwNTk0MS43NDgwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1734,"cells":{"problem_id":{"kind":"string","value":"342C"},"contest":{"kind":"string","value":"342"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Cupboard and Balloons"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Cupboard and Balloons</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>A girl named Xenia has a cupboard that looks like an arc from ahead. The arc is made of a semicircle with radius <span class=\"tex-span\"><i>r</i></span> (the cupboard's top) and two walls of height <span class=\"tex-span\"><i>h</i></span> (the cupboard's sides). The cupboard's depth is <span class=\"tex-span\"><i>r</i></span>, that is, it looks like a rectangle with base <span class=\"tex-span\"><i>r</i></span> and height <span class=\"tex-span\"><i>h</i> + <i>r</i></span> from the sides. The figure below shows what the cupboard looks like (the front view is on the left, the side view is on the right).</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/5475291fd7d6158be6eb19390045fce64f6b0e2d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>Xenia got lots of balloons for her birthday. The girl hates the mess, so she wants to store the balloons in the cupboard. Luckily, each balloon is a sphere with radius <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a4fcadf5554db1a524f8d91fc4f6fb6d9fa61718.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>. Help Xenia calculate the maximum number of balloons she can put in her cupboard. </p><p>You can say that a balloon is in the cupboard if you can't see any part of the balloon on the left or right view. The balloons in the cupboard can touch each other. It is not allowed to squeeze the balloons or deform them in any way. You can assume that the cupboard's walls are negligibly thin.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The single line contains two integers <span class=\"tex-span\"><i>r</i>, <i>h</i></span> <span class=\"tex-span\">(1 ≤ <i>r</i>, <i>h</i> ≤ 10<sup class=\"upper-index\">7</sup>)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the maximum number of balloons Xenia can put in the cupboard.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>5<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"7a1cc3c49814815d5f4357aad2707c4c\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"91a1e137bf92bd9ed30f9398e9597722ab5e17d3\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='7a1cc3c49814815d5f4357aad2707c4c'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F342%2Fproblem%2FC%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='7a1cc3c49814815d5f4357aad2707c4c'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/342\">Codeforces Round 199 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='7a1cc3c49814815d5f4357aad2707c4c'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/342/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Geometry, computational geometry\">\r\n geometry\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1900\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='7a1cc3c49814815d5f4357aad2707c4c'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3440\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='7a1cc3c49814815d5f4357aad2707c4c'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3440\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8795\" title=\"Codeforces Round #199 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1837:1838\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/8800\" title=\"Tutorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1840\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/342\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/342/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/342/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/342/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/342/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/342/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/342/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/342/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_3a32810fc86c8084824b3ad6fbc6e258599017af\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Cupboard and Balloons</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>A girl named Xenia has a cupboard that looks like an arc from ahead. The arc is made of a semicircle with radius <span class=\"tex-span\"><i>r</i></span> (the cupboard's top) and two walls of height <span class=\"tex-span\"><i>h</i></span> (the cupboard's sides). The cupboard's depth is <span class=\"tex-span\"><i>r</i></span>, that is, it looks like a rectangle with base <span class=\"tex-span\"><i>r</i></span> and height <span class=\"tex-span\"><i>h</i> + <i>r</i></span> from the sides. The figure below shows what the cupboard looks like (the front view is on the left, the side view is on the right).</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/5475291fd7d6158be6eb19390045fce64f6b0e2d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>Xenia got lots of balloons for her birthday. The girl hates the mess, so she wants to store the balloons in the cupboard. Luckily, each balloon is a sphere with radius <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a4fcadf5554db1a524f8d91fc4f6fb6d9fa61718.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Help Xenia calculate the maximum number of balloons she can put in her cupboard. </p><p>You can say that a balloon is in the cupboard if you can't see any part of the balloon on the left or right view. The balloons in the cupboard can touch each other. It is not allowed to squeeze the balloons or deform them in any way. You can assume that the cupboard's walls are negligibly thin.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The single line contains two integers <span class=\"tex-span\"><i>r</i>, <i>h</i></span> <span class=\"tex-span\">(1 ≤ <i>r</i>, <i>h</i> ≤ 10<sup class=\"upper-index\">7</sup>)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the maximum number of balloons Xenia can put in the cupboard.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>5<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:29</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bd56e84275ab',t:'MTY5NjY0NjAwOS41MTEwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Geometry, computational geometry\"]"},"short_tags":{"kind":"string","value":"[\"geometry\", \"*1900\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8800"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"779401b049eaea220649756fcc29cd29\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #199 (Div. 2) Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #199 (Div. 2) Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='779401b049eaea220649756fcc29cd29'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8800\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='779401b049eaea220649756fcc29cd29'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:41</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:41</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='779401b049eaea220649756fcc29cd29'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/HolkinPV\">HolkinPV</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/HolkinPV\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/HolkinPV\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/HolkinPV\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/HolkinPV\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/HolkinPV\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/HolkinPV\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/HolkinPV\" style=\"text-decoration:none;color:black !important;\">HolkinPV's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8855\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8800\"> <p>Codeforces Round #199 (Div. 2) Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/HolkinPV\" title=\"Candidate Master HolkinPV\" class=\"rated-user user-violet\">HolkinPV</a>,\r\n <span class=\"format-humantime\" title=\"Sep/07/2013 14:37\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/342/problem/A\" title=\"Codeforces Round 199 (Div. 2)\">342A - Xenia and Divisors</a></p><p>In this problem you should guess that exists only three valid groups of three </p><p>1) 1, 2, 4 </p><p>2) 1, 2, 6 </p><p>3) 1, 3, 6 </p><p>(You can see that integers 5 and 7 are bad).</p><p>So, we will greedy take these groups of three. If some integers will be not used, the answer is -1. In other case, print found answer.</p><p><a href=\"/contest/342/problem/B\" title=\"Codeforces Round 199 (Div. 2)\">342B - Xenia and Spies</a></p><p>The problem is solved by greedy algorithm. We will pass the note only in correct direction. Also, if we can pass the note at the current moment of time, we do it. In other case, we will hold it and don't give it to neighbors (we can make this action at any moment of time). Obviously this algorithm is correct. You should only implement it carefully.</p><p><a href=\"/contest/342/problem/C\" title=\"Codeforces Round 199 (Div. 2)\">342C - Cupboard and Balloons</a></p><p>In the problem you should carefully get formula. The optimal solution put marbles by two in a row. And then put one marble upon others if it possible. The most difficulties were to deal with this last phase. </p><p>In comments to the post were given formulas how to put the last marble (exactly in the middle). And there was a good beautiful illustration, which describes the situation.</p><p><a href=\"/contest/342/problem/D\" title=\"Codeforces Round 199 (Div. 2)\">342D - Xenia and Dominoes</a></p><p>In the problem you can count number of correct puzzles or substract number of incorrect puzzles from number of all puzzles. In any case you should count DP, where the state is <span class=\"tex-span\">(<i>j</i>, <i>mask</i>)</span> — <span class=\"tex-span\"><i>j</i></span> — number of the last full column, <span class=\"tex-span\"><i>mask</i></span> — mask of the last column. This problem is equivalent to the well known problem about domino tiling or the problem about parquet.</p><p>To get the solution of the whole problem I did the following. I try to attach one domino to each of 4 directions, then paint all three cells in black and count the number of correct puzzles. But in this case you will count some solutions several number of times. So you need to use inclusion exclusion formula for these 4 directions.</p><p><a href=\"/contest/342/problem/E\" title=\"Codeforces Round 199 (Div. 2)\">342E - Xenia and Tree</a></p><p>The problem can be solved in different ways. The most easy idea is sqrt-optimization. Split all queries into <span class=\"tex-span\"><i>sqrt</i>(<i>m</i>)</span> blocks. Each block we will process separately. Before processing each block, we should calculate minimum distances from every node to the closest red node using bfs. To answer the query we should update this value by shortest distances to red nodes in current block.</p><p>The solution becomes simple. Every <span class=\"tex-span\"><i>sqrt</i>(<i>m</i>)</span> queries we make simple bfs and for every node <span class=\"tex-span\"><i>v</i></span> WE calculate value <span class=\"tex-span\"><i>d</i>[<i>v</i>]</span> — the shortest distance to some red node from node <span class=\"tex-span\"><i>v</i></span>. Then to answer the query of type 2 you should calculate <span class=\"tex-span\"><i>min</i>(<i>d</i>[<i>v</i>], <i>dist</i>(<i>v</i>, <i>u</i>))</span>, where <span class=\"tex-span\"><i>u</i></span> — every red node, which becomes red in current block of length <span class=\"tex-span\"><i>sqrt</i>(<i>m</i>)</span>.</p><p>Distance between two nodes <span class=\"tex-span\"><i>dist</i>(<i>u</i>, <i>v</i>)</span> can be got using preprocessing for lca.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/342\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 199 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-230-8855\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"230\",\n blogEntryId: \"8800\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=199\" class=\"tag notice\" style=\"text-decoration: none;\">199</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8855\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+38</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8855\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/HolkinPV\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/HolkinPV\">\n HolkinPV\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/07/2013 14:37\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8800#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8800#comments\">\n 43\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8871\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (38)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145322\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/10/2013 19:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145322\" href=\"?#comment-145322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain problem D in more detail, I am not able to understand anything from what is posted. </p><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145322\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145419\" commentParentId=\"145322\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Smit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/19252/avatar/d7815c7f59ae1a65.jpg'/> </a>\n <div><a href=\"/profile/Smit\" title=\"Master Smit\" class=\"rated-user user-orange\">Smit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/12/2013 02:41\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145419\" href=\"?#comment-145419\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145322\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145419\" revisionCount=\"5\" revision=\"5\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">5</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145419\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"19252\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145419\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Solution is simple. let me explain it with a examples:</p><p>suppose we have filled all the empty blocks from column 0....i-1 and on ith column we have filled some of the empty blocks which is stored using mask 0,1,...,7</p><p>suppose if mask is currently 0 and i=2, so configuration could be something like this.</p> <pre><code>AA.X.\nAA.0.\nAA.X.\n</code></pre><p>blocks with A are already filled.</p><p>now we have two options, we might use some vertical block or not:</p> <pre><code>1. if we use vertical block and put it in first 2 rows. new state ----> (i,3)\n2. if we use vertical block and put it in last 2 rows. new state ----> (i,6)\n3. if we choose not to use vertical block we have to use 3 horizontal one ----> (i+1,7)\n</code></pre><p>now we are almost ready with solution and need to check while putting block if that box was empty earlier and which we put block near 0, we need to note this also.</p><p>I think, you should be able to understand my code now.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145419 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145419 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145419\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145868\" commentParentId=\"145419\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 14:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145868\" href=\"?#comment-145868\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145419\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145868\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145868\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could you please post the link to your solution.</p><p>I got the algorithm but I am lacking clarity over some points like considering the state (i,3), How does one keep track of whether a single vertical block was placed or 2 horizontal blocks covering the squares were placed.</p><p>Anyways, thanks for your explanation.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145868 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145868 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145868\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145885\" commentParentId=\"145868\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Smit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/19252/avatar/d7815c7f59ae1a65.jpg'/> </a>\n <div><a href=\"/profile/Smit\" title=\"Master Smit\" class=\"rated-user user-orange\">Smit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 16:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145885\" href=\"?#comment-145885\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145868\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145885\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"19252\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145885\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>solution: <a href=\"//codeforces.com/contest/342/submission/4424666\">http://codeforces.com/contest/342/submission/4424666</a></p><p>it does not matter whether it was vertical block or 2 horizontal block. (i,3) tells that all the blocks in first i-1 columns are filled and in this column there is only last row left to be filled.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145885 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145885 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145885\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145656\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rhd\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78747/avatar/b4494f9b3e154714.jpg'/> </a>\n <div><a href=\"/profile/rhd\" title=\"Unrated, rhd\" class=\"rated-user user-black\">rhd</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2013 04:45\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145656\" href=\"?#comment-145656\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145656\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145656\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78747\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145656\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>.d.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145656 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145656 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145656\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145671\" commentParentId=\"145656\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Qubit01\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1399/avatar/c963814250395100.jpg'/> </a>\n <div><a href=\"/profile/Qubit01\" title=\"Expert Qubit01\" class=\"rated-user user-blue\">Qubit01</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2013 12:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145671\" href=\"?#comment-145671\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145656\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145671\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1399\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145671\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Assume that you have the distances from vertex with index <em>1</em> to every vertex <em>u</em> in a vector <em>d[]</em>.</p><p>Define <em>lca(x, y)</em> the lowest common ancestor for vertex <em>x</em> and <em>y</em>. You must find out the distance from <em>v</em> to <em>u</em>. </p><p>The result is <em>d[u] + d[v] — 2 * lca(u, v)</em> because you add twice the distance from vertex <em>1</em> to <em>lca(u, v)</em> (that's where the 2 roads intersects). You can draw a tree on a paper and and work with some examples, it will be clearer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145671 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145671 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145671\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146192\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lkjslkjdlk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34453/avatar/944f96e876fade4b.jpg'/> </a>\n <div><a href=\"/profile/lkjslkjdlk\" title=\"Specialist lkjslkjdlk\" class=\"rated-user user-cyan\">lkjslkjdlk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 14:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146192\" href=\"?#comment-146192\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146192\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34453\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146192\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could you please tell me the complexity of the Problem E?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146192 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146192 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146192\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146196\" commentParentId=\"146192\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lkjslkjdlk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34453/avatar/944f96e876fade4b.jpg'/> </a>\n <div><a href=\"/profile/lkjslkjdlk\" title=\"Specialist lkjslkjdlk\" class=\"rated-user user-cyan\">lkjslkjdlk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 16:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146196\" href=\"?#comment-146196\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146192\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146196\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34453\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146196\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here is my solution: <a href=\"//codeforces.com/contest/342/submission/4509629\">http://codeforces.com/contest/342/submission/4509629</a> The complexity seems to be O((n+m)*sqrt(m)). But it still gets TLE.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146196 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146196 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146196\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"458577\" commentParentId=\"146196\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mahagoni\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/567134/avatar/f60a9c806d357d9e.jpg'/> </a>\n <div><a href=\"/profile/Mahagoni\" title=\"Expert Mahagoni\" class=\"rated-user user-blue\">Mahagoni</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2018 00:21\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-458577\" href=\"?#comment-458577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146196\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"458577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"567134\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-458577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><em>O(n*sqrt(m)*log(n))</em></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-458577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-458577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-458577\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"673071\" commentParentId=\"146192\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/muzzaleeni\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/621091/avatar/e6a7f915e328dcd8.jpg'/> </a>\n <div><a href=\"/profile/muzzaleeni\" title=\"Pupil muzzaleeni\" class=\"rated-user user-green\">muzzaleeni</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/02/2020 11:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-673071\" href=\"?#comment-673071\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146192\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"673071\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"621091\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-673071\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>\\begin{equation}m \\cdot\\sqrt{m}\\cdot\\log_2{(n)}\\end{equation}</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-673071 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-673071 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-673071\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"937837\" commentParentId=\"673071\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Phantom_Performer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1746799/avatar/bc1dcacc56722125.jpg'/> </a>\n <div><a href=\"/profile/Phantom_Performer\" title=\"Master Phantom_Performer\" class=\"rated-user user-orange\">Phantom_Performer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/30/2022 17:45\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-937837\" href=\"?#comment-937837\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-673071\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"937837\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1746799\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-937837\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can precalculate the lca of nodes in Mlogn</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-937837 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-937837 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-937837\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"156861\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Harun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48372/avatar/15bf49d98279c433.jpg'/> </a>\n <div><a href=\"/profile/Harun\" title=\"Expert Harun\" class=\"rated-user user-blue\">Harun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/05/2014 22:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-156861\" href=\"?#comment-156861\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"156861\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48372\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-156861\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In E problem , there isn't any boundary case like chain. Then O(N*N) solution can get AC.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-156861 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-156861 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-156861\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"545136\" commentParentId=\"156861\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SevenDeadlySins\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/430874/avatar/b011182bef4f60f0.jpg'/> </a>\n <div><a href=\"/profile/SevenDeadlySins\" title=\"Pupil SevenDeadlySins\" class=\"rated-user user-green\">SevenDeadlySins</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2019 13:59\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-545136\" href=\"?#comment-545136\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-156861\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"545136\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"430874\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-545136\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>did u code in cpp?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-545136 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-545136 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-545136\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"545137\" commentParentId=\"545136\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Harun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48372/avatar/15bf49d98279c433.jpg'/> </a>\n <div><a href=\"/profile/Harun\" title=\"Expert Harun\" class=\"rated-user user-blue\">Harun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2019 14:04\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-545137\" href=\"?#comment-545137\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-545136\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"545137\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48372\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-545137\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don’t even remember what I had for dinner last night and you’re here asking me about a code I wrote 6 years ago. That’s like a lot of months :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-545137 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-545137 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-545137\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"545138\" commentParentId=\"545137\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SevenDeadlySins\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/430874/avatar/b011182bef4f60f0.jpg'/> </a>\n <div><a href=\"/profile/SevenDeadlySins\" title=\"Pupil SevenDeadlySins\" class=\"rated-user user-green\">SevenDeadlySins</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2019 14:09\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-545138\" href=\"?#comment-545138\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-545137\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"545138\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"430874\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-545138\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>That can be answered with what language u used to code with... But anyway you have a point... and I got the ans after stalking your profile... Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-545138 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-545138 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-545138\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"174599\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dtalamas24\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60129/avatar/200478a7b9850d4b.jpg'/> </a>\n <div><a href=\"/profile/dtalamas24\" title=\"Candidate Master dtalamas24\" class=\"rated-user user-violet\">dtalamas24</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2014 09:33\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-174599\" href=\"?#comment-174599\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"174599\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"174599\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60129\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-174599\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Any online solutions for problem E ? Or different solutions to E?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-174599 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-174599 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-174599\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176403\" commentParentId=\"174599\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kllp\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/100053/avatar/44882b58f6756412.jpg'/> </a>\n <div><a href=\"/profile/kllp\" title=\"Master kllp\" class=\"rated-user user-orange\">kllp</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/02/2014 23:38\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176403\" href=\"?#comment-176403\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-174599\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"176403\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"100053\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176403\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My solution uses Heavy-light decomposition and segment trees. Complexity is O(N log^2 N). <a href=\"//codeforces.com/contest/342/submission/6999318\">http://codeforces.com/contest/342/submission/6999318</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176403 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176403 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176403\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"181789\" commentParentId=\"176403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Harun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48372/avatar/15bf49d98279c433.jpg'/> </a>\n <div><a href=\"/profile/Harun\" title=\"Expert Harun\" class=\"rated-user user-blue\">Harun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/09/2014 17:53\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-181789\" href=\"?#comment-181789\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"181789\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48372\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-181789\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could you explain your idea ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-181789 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-181789 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-181789\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"252934\" commentParentId=\"176403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/manmodeashish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/manmodeashish\" title=\"Specialist manmodeashish\" class=\"rated-user user-cyan\">manmodeashish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/28/2015 12:33\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-252934\" href=\"?#comment-252934\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"252934\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"226988\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-252934\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>very good. It was really helpful. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-252934 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-252934 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-252934\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"442050\" commentParentId=\"176403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cai_lw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/325977/avatar/202b61935928944.jpg'/> </a>\n <div><a href=\"/profile/cai_lw\" title=\"International Master cai_lw\" class=\"rated-user user-orange\">cai_lw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/02/2018 17:36\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-442050\" href=\"?#comment-442050\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"442050\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"325977\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-442050\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We can achieve O(NlogN) if we store each "heavy chains" in separate segment trees. For each operation, all queries and updates, except the beginning one, are on the whole chain, and only takes O(1). Therefore, each operation takes O(logN)*O(1)+O(1)*O(logN)=O(logN)</p><p><a href=\"//codeforces.com/contest/342/submission/39871066\">My solution</a> (it doesn't run faster in practice though)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-442050 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-442050 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-442050\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"213929\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mindbeats\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/56717/avatar/bcddf2e5600931f3.jpg'/> </a>\n <div><a href=\"/profile/mindbeats\" title=\"Expert mindbeats\" class=\"rated-user user-blue\">mindbeats</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2015 00:14\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-213929\" href=\"?#comment-213929\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"213929\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"56717\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-213929\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in problem E, the complexity is O(N * sqrtN * logN).... logN because of the LCA part it doesn't pass the time</p><p>how did you handle this !!?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-213929 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-213929 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-213929\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"937838\" commentParentId=\"213929\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Phantom_Performer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1746799/avatar/bc1dcacc56722125.jpg'/> </a>\n <div><a href=\"/profile/Phantom_Performer\" title=\"Master Phantom_Performer\" class=\"rated-user user-orange\">Phantom_Performer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/30/2022 17:45\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-937838\" href=\"?#comment-937838\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-213929\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"937838\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1746799\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-937838\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can precalculate the lca of nodes in Mlogn</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-937838 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-937838 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-937838\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"937911\" commentParentId=\"937838\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mindbeats\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/56717/avatar/bcddf2e5600931f3.jpg'/> </a>\n <div><a href=\"/profile/mindbeats\" title=\"Expert mindbeats\" class=\"rated-user user-blue\">mindbeats</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/31/2022 05:01\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-937911\" href=\"?#comment-937911\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-937838\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"937911\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"56717\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-937911\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>oh 7 years to get an answer...that was really too fast! :D </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-937911 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-937911 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-937911\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"316277\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2016 18:20\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-316277\" href=\"?#comment-316277\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"316277\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"316277\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-316277\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Deleted</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-316277 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-316277 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-316277\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"335462\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/....\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/....\" title=\"Expert ....\" class=\"rated-user user-blue\">....</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/04/2017 21:36\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-335462\" href=\"?#comment-335462\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"335462\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"335462\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"490997\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-335462\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem <a href=\"/contest/342/problem/E\" title=\"Codeforces Round 199 (Div. 2)\">342E - Xenia and Tree</a>, I came across a centroid decomposition solution <a href=\"/contest/342/submission/23224047\" title=\"Submission 23224047 by raiden_11\">23224047</a>. I have gone through the solution, but I am not able to convince myself about the correctness of the algorithm and the reason as to why query method is correct(or works). Please help!</p><p>PS: <a class=\"rated-user user-violet\" href=\"/profile/HolkinPV\" title=\"Candidate Master HolkinPV\">HolkinPV</a>, can you please help?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-335462 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-335462 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-335462\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"528302\" commentParentId=\"335462\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/VLADO\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/630234/avatar/e6872ed793f74338.jpg'/> </a>\n <div><a href=\"/profile/VLADO\" title=\"Expert VLADO\" class=\"rated-user user-blue\">VLADO</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/19/2019 15:37\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-528302\" href=\"?#comment-528302\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-335462\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"528302\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"630234\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-528302\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm a bit late but the solution is explained <a href=\"https://threads-iiith.quora.com/Centroid-Decomposition-of-a-Tree\">here</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-528302 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-528302 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-528302\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"370331\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/S.Jindal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/508955/avatar/43cfebadfb0dea2c.jpg'/> </a>\n <div><a href=\"/profile/S.Jindal\" title=\"Candidate Master S.Jindal\" class=\"rated-user user-violet\">S.Jindal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/29/2017 07:28\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-370331\" href=\"?#comment-370331\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"370331\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"508955\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-370331\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve Div1,C if we have to return the maximum distance to any red node instead of min distance...?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-370331 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-370331 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-370331\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371401\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nitesh_gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/454345/avatar/88dd212e02074fb0.jpg'/> </a>\n <div><a href=\"/profile/nitesh_gupta\" title=\"Master nitesh_gupta\" class=\"rated-user user-orange\">nitesh_gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/03/2017 11:52\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371401\" href=\"?#comment-371401\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"371401\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"371401\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"454345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371401\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"Distance between two nodes dist(u, v) can be got using preprocessing for lca." - Xenia and Tree</p><p>Can anyone explain me how to do it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371401 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371401 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371401\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371545\" commentParentId=\"371401\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MasT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/451310/avatar/10587ffa9ae01331.jpg'/> </a>\n <div><a href=\"/profile/MasT\" title=\"Expert MasT\" class=\"rated-user user-blue\">MasT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2017 07:00\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371545\" href=\"?#comment-371545\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371401\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"371545\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"371545\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"451310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371545\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Notice that <code>dist(u, v) = dist(root, u) + dist(root, v) - 2 * dist(root, l)</code>, where l is the LCA of u and v</p><p>1) Use a DFS to find the distance from node 1 (the root) to every other node. Let <code>rootDist[n]</code> by the distance from node 1 to node n. The DFS should also find the parent of each node, and the depth of each node from the root. Let <code>parent[n]</code> be the parent of node n and <code>depth[n]</code> be the depth of node n.</p><p>Example DFS code:</p> <pre><code>//Let MAX be the number of maximum nodes\nvector<int> adj[MAX];\nint rootDist[MAX], parent[MAX], depth[MAX];\n\n// cur = Current traversing node\n// prev = Node traversed before this one\nint dfs(int cur, int prev){\n parent[cur] = prev;\n\n for(int child : adj[cur]){\n if(child != prev){\n depth[child] = depth[cur] + 1;\n rootDist[child] = rootDist[cur] + 1;\n // Note: In the case of an unweighted tree,\n // depth[n] == rootDist[n]\n\n dfs(child, cur);\n\n }\n }\n}\n\ndfs(1, -1);\n</code></pre><p>2) Build a sparse table. <code>sparse[u][i]</code> stores the 2**i-th parent of u, or <code>-1</code> if that parent doesn't exist. Note that <code>sparse[u][0] = parent[n]</code>. The sparse table can be built by:</p> <pre><code>// N = number of nodes as given in input\n// LN = ceil(log2(Max number of nodes))\n// Using 1-indexing for nodes\nint sparse[MAX][LN];\nmemset(sparse, -1, sizeof sparse);\n\nfor(int u = 1; u <= N; u++)\n sparse[u][0] = parent[u];\n\nfor(int i = 1; i < LN; i++)\n for(int u = 1; u <= N; u++)\n //if the node has a 2**(i - 1)th parent\n if(sparse[u][i - 1] != -1)\n // the 2**i-th parent of u is equal to\n // the 2**(i - 1)th parent of 2**(i - 1)th parent of u\n sparse[u][i] = sparse [ sparse[u][i - 1] ] [i - 1];\n</code></pre><p>3) To query the lca of u and v, we do the following steps:</p> <ol> <li>If u has a smaller depth than v, swap them</li> <li>Find the ancestor of u with the same depth of v</li> <li>If u and v are the same node, return it</li> <li>Find the highest (least depth) ancestor of u and v (let's call them u' and v') such that u' is not v'</li> <li>Return the parent of u' (which is equal to the parent of v')</li> </ol><p>Here is the code for the query:</p> <pre><code>int lca(int u, int v){\n if(depth[u] < depth[v])\n swap(u, v);\n\n // We use sparse table so we jump 2**i parents each time\n // Taking only log time\n for(int i = LN - 1; i >= 0; i--)\n // If the 2**i-th parent of u isn't higher than v\n if(depth[ sparse[u][i] ] >= depth[v])\n // Go up 2**i parents\n u = sparse[u][i];\n\n // At this point, depth[u] == depth[v]\n // If they happen to be the same node, that is the LCA\n if(u == v)\n return u;\n\n for(int i = LN - 1; i >= 0; i--){\n // If their ancestors aren't the same\n if(sparse[u][i] != sparse[v][i]){\n // Go up to their ancestor\n u = sparse[u][i];\n v = sparse[v][i];\n }\n }\n\n // At this point, they're at the highest ancestor\n // such that they're not the same, so one parent above\n // must be their LCA\n\n // 2**0 = 1, return first parent of u\n return sparse[u][0];\n // this is also equal to sparse[v][0]\n}\n</code></pre><p>And finally, to put it all together, to query distance</p> <pre><code>int dist(int u, int v){\n int l = lca(u, v);\n return rootDist[u] + rootDist[v] - 2 * rootDist[l];\n}\n</code></pre><p>Building the LCA sparse table takes <code>O(n log n)</code> time while querying takes <code>O(log n)</code> time</p><p>(I wrote this from memory; please tell me if there are any mistakes or if any part is confusing)</p><p><a href=\"https://www.topcoder.com/community/data-science/data-science-tutorials/range-minimum-query-and-lowest-common-ancestor/\">Source/Additional reading</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371545 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371545 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371545\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371617\" commentParentId=\"371545\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nitesh_gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/454345/avatar/88dd212e02074fb0.jpg'/> </a>\n <div><a href=\"/profile/nitesh_gupta\" title=\"Master nitesh_gupta\" class=\"rated-user user-orange\">nitesh_gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2017 20:32\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371617\" href=\"?#comment-371617\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371545\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"371617\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"454345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371617\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for your help. You explained very well.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371617 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371617 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371617\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"425765\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sonupmandal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/356694/avatar/a3df14f7c5265075.jpg'/> </a>\n <div><a href=\"/profile/sonupmandal\" title=\"Pupil sonupmandal\" class=\"rated-user user-green\">sonupmandal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/18/2018 07:38\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-425765\" href=\"?#comment-425765\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"425765\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"356694\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-425765\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to do this - Calculate minimum distances from every node to the closest red node using bfs.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-425765 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-425765 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-425765\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"432106\" commentParentId=\"425765\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kayak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/700181/avatar/ec3f04c38ba70bde.jpg'/> </a>\n <div><a href=\"/profile/kayak\" title=\"Expert kayak\" class=\"rated-user user-blue\">kayak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2018 18:49\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-432106\" href=\"?#comment-432106\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-425765\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"432106\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"432106\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"700181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-432106\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Store all nodes which are currently red in a vector redlist. Create an queue bfslist for bfs, and create a array <code>dist[v] = Distance from v to the nearest red node, 0 if v is itself red</code> and initialize an empty queue. Now for all red vertices <span class=\"tex-span\"><i>v</i></span>, let <code>dist[v] = 0</code> and push all the neighbours <span class=\"tex-span\"><i>u</i></span> of the red vertices which are not red into this queue, and for all such <span class=\"tex-span\"><i>u</i></span>, let <code>dist[u] = 1, isdiscovered[u] = 1</code>. Now it's just regular bfs: while the queue is nonempty, pop the first element <code>w</code> from the queue, and add all the neighbours <code>y</code> of <code>w</code> not already discovered to the queue, and let <code>dist[y] = dist[w] +1, isdiscovered[y] = 1</code>. Here's a code implementing it:</p> <pre><code>void bfs(){\n std::queue<int> bfslist;\n int isdisc[N] = {0};\n for (int i = 0; i < red.size(); i +=1){\n int a = red[i];\n reddist[a] = 0;\n isdisc[i] = 1;\n for (int j = 0; j < adjlist[a].size(); j +=1){\n int b = adjlist[a][j];\n if ((isred[b] == 1) && (isdisc[b] == 0)){\n bfslist.push(b);\n reddist[b] = 1;\n isdisc[b] = 1;\n }\n }\n }\n while (!bfslist.empty()){\n int a = bfslist.front();\n bfslist.pop();\n for (int i = 0; i < adjlist[a].size(); i +=1){\n int b = adjlist[a][i];\n if ((isred[b] ==1) && (isdisc[b] == 0)){\n bfslist.push(b);\n reddist[b] = reddist[a]+1;\n isdisc[b] = 1;\n }\n }\n }\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-432106 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-432106 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-432106\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"446034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arjitkansal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/542324/avatar/cb05cf6d94faff9c.jpg'/> </a>\n <div><a href=\"/profile/arjitkansal\" title=\"Master arjitkansal\" class=\"rated-user user-orange\">arjitkansal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/18/2018 09:51\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-446034\" href=\"?#comment-446034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"446034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"542324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-446034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, can anyone please help me debug this code for Problem E. </p><p><a href=\"https://codeforces.com/contest/342/submission/39819558\">https://codeforces.com/contest/342/submission/39819558</a></p><p>It has been days and I've not been able to find the error.</p><p>I used 'Centroid Decomposition'.</p><p>Thanks in Advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-446034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-446034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-446034\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"566831\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ac_97\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1211001/avatar/6e08c927b196de27.jpg'/> </a>\n <div><a href=\"/profile/ac_97\" title=\"Specialist ac_97\" class=\"rated-user user-cyan\">ac_97</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/24/2019 00:32\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-566831\" href=\"?#comment-566831\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"566831\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1211001\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-566831\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem Div2 E, can someone share the code implementing the sqrt optimization trick. Are there any resources for this technique ? In what all cases can this technique be applied ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-566831 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-566831 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-566831\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"598414\" commentParentId=\"566831\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Skeef79\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631759/avatar/3033511aaec49179.jpg'/> </a>\n <div><a href=\"/profile/Skeef79\" title=\"Candidate Master Skeef79\" class=\"rated-user user-violet\">Skeef79</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/06/2020 13:06\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-598414\" href=\"?#comment-598414\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-566831\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"598414\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"631759\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-598414\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://pastebin.com/cCYBLvjs\">https://pastebin.com/cCYBLvjs</a></p><p><a href=\"https://codeforces.com/contest/342/submission/75643716\">https://codeforces.com/contest/342/submission/75643716</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-598414 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-598414 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-598414\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"584071\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mooncrater\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/656776/avatar/d19b34b1e226e4ad.jpg'/> </a>\n <div><a href=\"/profile/Mooncrater\" title=\"Specialist Mooncrater\" class=\"rated-user user-cyan\">Mooncrater</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/26/2020 20:31\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-584071\" href=\"?#comment-584071\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"584071\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"656776\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-584071\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div2 C, what comments?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-584071 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-584071 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-584071\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"913528\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mynameisminh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/mynameisminh\" title=\"Newbie mynameisminh\" class=\"rated-user user-gray\">mynameisminh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2022 19:24\">17 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-913528\" href=\"?#comment-913528\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"913528\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2253580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-913528\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can somebody help me with problems 342E. Here's my source code: <a href=\"https://codeforces.com/problemset/submission/342/157723527\">https://codeforces.com/problemset/submission/342/157723527</a></p><p>I still don't know why I got TLE. Thanks so much!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-913528 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-913528 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-913528\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"924618\" commentParentId=\"913528\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lite_27\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2584952/avatar/d7812158a0f2af9b.jpg'/> </a>\n <div><a href=\"/profile/lite_27\" title=\"Specialist lite_27\" class=\"rated-user user-cyan\">lite_27</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2022 23:07\">16 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-924618\" href=\"?#comment-924618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-913528\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"924618\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"924618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2584952\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-924618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-924618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-924618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-924618\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8871\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8871 = true;\r\nvar lastPreviewContent8871 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8871] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8871] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8855\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8855, _tta: Codeforces.tta(), topicRevisionId: 31374, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8855\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8855, _tta: Codeforces.tta(), topicRevisionId: 31374, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:21</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'81287486695d9d99',t:'MTY5NjcwNTk0MS43NDgwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1735,"cells":{"problem_id":{"kind":"string","value":"342D"},"contest":{"kind":"string","value":"342"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Xenia and Dominoes"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Xenia and Dominoes</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Xenia likes puzzles very much. She is especially fond of the puzzles that consist of domino pieces. Look at the picture that shows one of such puzzles.</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/0b5ec283b17906cd7f011779b7cbe31ce55f4584.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>A puzzle is a <span class=\"tex-span\">3 × <i>n</i></span> table with forbidden cells (black squares) containing dominoes (colored rectangles on the picture). A puzzle is called <span class=\"tex-font-style-it\">correct</span> if it meets the following conditions:</p><ul> <li> each domino occupies exactly two non-forbidden cells of the table; </li><li> no two dominoes occupy the same table cell; </li><li> exactly one non-forbidden cell of the table is unoccupied by any domino (it is marked by a circle in the picture). </li></ul><p>To solve the puzzle, you need multiple steps to transport an empty cell from the starting position to some specified position. A move is transporting a domino to the empty cell, provided that the puzzle stays correct. <span class=\"tex-font-style-bf\">The horizontal dominoes can be moved only horizontally, and vertical dominoes can be moved only vertically. You can't rotate dominoes.</span> The picture shows a probable move.</p><p>Xenia has a <span class=\"tex-span\">3 × <i>n</i></span> table with forbidden cells and a cell marked with a circle. Also, Xenia has very many identical dominoes. Now Xenia is wondering, how many distinct correct puzzles she can make if she puts dominoes on the existing table. Also, Xenia wants the circle-marked cell to be empty in the resulting puzzle. The puzzle must contain at least one move.</p><p>Help Xenia, count the described number of puzzles. As the described number can be rather large, print the remainder after dividing it by <span class=\"tex-span\">1000000007</span> <span class=\"tex-span\">(10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(3 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">4</sup>)</span> — the puzzle's size. Each of the following three lines contains <span class=\"tex-span\"><i>n</i></span> characters — the description of the table. The <span class=\"tex-span\"><i>j</i></span>-th character of the <span class=\"tex-span\"><i>i</i></span>-th line equals \"<span class=\"tex-font-style-tt\">X</span>\" if the corresponding cell is forbidden; it equals \"<span class=\"tex-font-style-tt\">.</span>\", if the corresponding cell is non-forbidden and \"<span class=\"tex-font-style-tt\">O</span>\", if the corresponding cell is marked with a circle.</p><p>It is guaranteed that exactly one cell in the table is marked with a circle. It is guaranteed that all cells of a given table having at least one common point with the marked cell is non-forbidden.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single number — the answer to the problem modulo <span class=\"tex-span\">1000000007</span> <span class=\"tex-span\">(10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>....X<br/>.O...<br/>...X.<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>.....<br/>.O...<br/>.....<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>...<br/>...<br/>..O<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Two puzzles are considered distinct if there is a pair of cells that contain one domino in one puzzle and do not contain it in the other one.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"e4c06b0dfc23a5a315d132f5b1ecee28\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"91a1e137bf92bd9ed30f9398e9597722ab5e17d3\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='e4c06b0dfc23a5a315d132f5b1ecee28'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F342%2Fproblem%2FD%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='e4c06b0dfc23a5a315d132f5b1ecee28'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/342\">Codeforces Round 199 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='e4c06b0dfc23a5a315d132f5b1ecee28'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/342/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Bitmasks\">\r\n bitmasks\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dfs and similar\">\r\n dfs and similar\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2100\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='e4c06b0dfc23a5a315d132f5b1ecee28'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3441\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='e4c06b0dfc23a5a315d132f5b1ecee28'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3441\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8795\" title=\"Codeforces Round #199 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1837:1838\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/8800\" title=\"Tutorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1840\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/342\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/342/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/342/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/342/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/342/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/342/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/342/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/342/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_792da2c27f79e15146e640f32831af8716d56eb0\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Xenia and Dominoes</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Xenia likes puzzles very much. She is especially fond of the puzzles that consist of domino pieces. Look at the picture that shows one of such puzzles.</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/0b5ec283b17906cd7f011779b7cbe31ce55f4584.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>A puzzle is a <span class=\"tex-span\">3 × <i>n</i></span> table with forbidden cells (black squares) containing dominoes (colored rectangles on the picture). A puzzle is called <span class=\"tex-font-style-it\">correct</span> if it meets the following conditions:</p><ul> <li> each domino occupies exactly two non-forbidden cells of the table; </li><li> no two dominoes occupy the same table cell; </li><li> exactly one non-forbidden cell of the table is unoccupied by any domino (it is marked by a circle in the picture). </li></ul><p>To solve the puzzle, you need multiple steps to transport an empty cell from the starting position to some specified position. A move is transporting a domino to the empty cell, provided that the puzzle stays correct. <span class=\"tex-font-style-bf\">The horizontal dominoes can be moved only horizontally, and vertical dominoes can be moved only vertically. You can't rotate dominoes.</span> The picture shows a probable move.</p><p>Xenia has a <span class=\"tex-span\">3 × <i>n</i></span> table with forbidden cells and a cell marked with a circle. Also, Xenia has very many identical dominoes. Now Xenia is wondering, how many distinct correct puzzles she can make if she puts dominoes on the existing table. Also, Xenia wants the circle-marked cell to be empty in the resulting puzzle. The puzzle must contain at least one move.</p><p>Help Xenia, count the described number of puzzles. As the described number can be rather large, print the remainder after dividing it by <span class=\"tex-span\">1000000007</span> <span class=\"tex-span\">(10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(3 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">4</sup>)</span> — the puzzle's size. Each of the following three lines contains <span class=\"tex-span\"><i>n</i></span> characters — the description of the table. The <span class=\"tex-span\"><i>j</i></span>-th character of the <span class=\"tex-span\"><i>i</i></span>-th line equals "<span class=\"tex-font-style-tt\">X</span>" if the corresponding cell is forbidden; it equals "<span class=\"tex-font-style-tt\">.</span>", if the corresponding cell is non-forbidden and "<span class=\"tex-font-style-tt\">O</span>", if the corresponding cell is marked with a circle.</p><p>It is guaranteed that exactly one cell in the table is marked with a circle. It is guaranteed that all cells of a given table having at least one common point with the marked cell is non-forbidden.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single number — the answer to the problem modulo <span class=\"tex-span\">1000000007</span> <span class=\"tex-span\">(10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />....X<br />.O...<br />...X.<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />.....<br />.O...<br />.....<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />...<br />...<br />..O<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Two puzzles are considered distinct if there is a pair of cells that contain one domino in one puzzle and do not contain it in the other one.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:30</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bd5f0dbb9d8c',t:'MTY5NjY0NjAxMC44NTAwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Bitmasks\", \"Dfs and similar\", \"Dynamic programming\"]"},"short_tags":{"kind":"string","value":"[\"bitmasks\", \"dfs and similar\", \"dp\", \"*2100\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8800"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"779401b049eaea220649756fcc29cd29\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #199 (Div. 2) Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #199 (Div. 2) Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='779401b049eaea220649756fcc29cd29'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8800\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='779401b049eaea220649756fcc29cd29'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:41</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:41</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='779401b049eaea220649756fcc29cd29'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/HolkinPV\">HolkinPV</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/HolkinPV\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/HolkinPV\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/HolkinPV\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/HolkinPV\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/HolkinPV\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/HolkinPV\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/HolkinPV\" style=\"text-decoration:none;color:black !important;\">HolkinPV's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8855\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8800\"> <p>Codeforces Round #199 (Div. 2) Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/HolkinPV\" title=\"Candidate Master HolkinPV\" class=\"rated-user user-violet\">HolkinPV</a>,\r\n <span class=\"format-humantime\" title=\"Sep/07/2013 14:37\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/342/problem/A\" title=\"Codeforces Round 199 (Div. 2)\">342A - Xenia and Divisors</a></p><p>In this problem you should guess that exists only three valid groups of three </p><p>1) 1, 2, 4 </p><p>2) 1, 2, 6 </p><p>3) 1, 3, 6 </p><p>(You can see that integers 5 and 7 are bad).</p><p>So, we will greedy take these groups of three. If some integers will be not used, the answer is -1. In other case, print found answer.</p><p><a href=\"/contest/342/problem/B\" title=\"Codeforces Round 199 (Div. 2)\">342B - Xenia and Spies</a></p><p>The problem is solved by greedy algorithm. We will pass the note only in correct direction. Also, if we can pass the note at the current moment of time, we do it. In other case, we will hold it and don't give it to neighbors (we can make this action at any moment of time). Obviously this algorithm is correct. You should only implement it carefully.</p><p><a href=\"/contest/342/problem/C\" title=\"Codeforces Round 199 (Div. 2)\">342C - Cupboard and Balloons</a></p><p>In the problem you should carefully get formula. The optimal solution put marbles by two in a row. And then put one marble upon others if it possible. The most difficulties were to deal with this last phase. </p><p>In comments to the post were given formulas how to put the last marble (exactly in the middle). And there was a good beautiful illustration, which describes the situation.</p><p><a href=\"/contest/342/problem/D\" title=\"Codeforces Round 199 (Div. 2)\">342D - Xenia and Dominoes</a></p><p>In the problem you can count number of correct puzzles or substract number of incorrect puzzles from number of all puzzles. In any case you should count DP, where the state is <span class=\"tex-span\">(<i>j</i>, <i>mask</i>)</span> — <span class=\"tex-span\"><i>j</i></span> — number of the last full column, <span class=\"tex-span\"><i>mask</i></span> — mask of the last column. This problem is equivalent to the well known problem about domino tiling or the problem about parquet.</p><p>To get the solution of the whole problem I did the following. I try to attach one domino to each of 4 directions, then paint all three cells in black and count the number of correct puzzles. But in this case you will count some solutions several number of times. So you need to use inclusion exclusion formula for these 4 directions.</p><p><a href=\"/contest/342/problem/E\" title=\"Codeforces Round 199 (Div. 2)\">342E - Xenia and Tree</a></p><p>The problem can be solved in different ways. The most easy idea is sqrt-optimization. Split all queries into <span class=\"tex-span\"><i>sqrt</i>(<i>m</i>)</span> blocks. Each block we will process separately. Before processing each block, we should calculate minimum distances from every node to the closest red node using bfs. To answer the query we should update this value by shortest distances to red nodes in current block.</p><p>The solution becomes simple. Every <span class=\"tex-span\"><i>sqrt</i>(<i>m</i>)</span> queries we make simple bfs and for every node <span class=\"tex-span\"><i>v</i></span> WE calculate value <span class=\"tex-span\"><i>d</i>[<i>v</i>]</span> — the shortest distance to some red node from node <span class=\"tex-span\"><i>v</i></span>. Then to answer the query of type 2 you should calculate <span class=\"tex-span\"><i>min</i>(<i>d</i>[<i>v</i>], <i>dist</i>(<i>v</i>, <i>u</i>))</span>, where <span class=\"tex-span\"><i>u</i></span> — every red node, which becomes red in current block of length <span class=\"tex-span\"><i>sqrt</i>(<i>m</i>)</span>.</p><p>Distance between two nodes <span class=\"tex-span\"><i>dist</i>(<i>u</i>, <i>v</i>)</span> can be got using preprocessing for lca.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/342\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 199 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-230-8855\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"230\",\n blogEntryId: \"8800\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=199\" class=\"tag notice\" style=\"text-decoration: none;\">199</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8855\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+38</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8855\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/HolkinPV\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/HolkinPV\">\n HolkinPV\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/07/2013 14:37\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8800#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8800#comments\">\n 43\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8871\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (38)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145322\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/10/2013 19:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145322\" href=\"?#comment-145322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain problem D in more detail, I am not able to understand anything from what is posted. </p><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145322\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145419\" commentParentId=\"145322\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Smit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/19252/avatar/d7815c7f59ae1a65.jpg'/> </a>\n <div><a href=\"/profile/Smit\" title=\"Master Smit\" class=\"rated-user user-orange\">Smit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/12/2013 02:41\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145419\" href=\"?#comment-145419\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145322\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145419\" revisionCount=\"5\" revision=\"5\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">5</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145419\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"19252\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145419\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Solution is simple. let me explain it with a examples:</p><p>suppose we have filled all the empty blocks from column 0....i-1 and on ith column we have filled some of the empty blocks which is stored using mask 0,1,...,7</p><p>suppose if mask is currently 0 and i=2, so configuration could be something like this.</p> <pre><code>AA.X.\nAA.0.\nAA.X.\n</code></pre><p>blocks with A are already filled.</p><p>now we have two options, we might use some vertical block or not:</p> <pre><code>1. if we use vertical block and put it in first 2 rows. new state ----> (i,3)\n2. if we use vertical block and put it in last 2 rows. new state ----> (i,6)\n3. if we choose not to use vertical block we have to use 3 horizontal one ----> (i+1,7)\n</code></pre><p>now we are almost ready with solution and need to check while putting block if that box was empty earlier and which we put block near 0, we need to note this also.</p><p>I think, you should be able to understand my code now.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145419 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145419 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145419\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145868\" commentParentId=\"145419\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 14:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145868\" href=\"?#comment-145868\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145419\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145868\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145868\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could you please post the link to your solution.</p><p>I got the algorithm but I am lacking clarity over some points like considering the state (i,3), How does one keep track of whether a single vertical block was placed or 2 horizontal blocks covering the squares were placed.</p><p>Anyways, thanks for your explanation.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145868 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145868 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145868\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145885\" commentParentId=\"145868\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Smit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/19252/avatar/d7815c7f59ae1a65.jpg'/> </a>\n <div><a href=\"/profile/Smit\" title=\"Master Smit\" class=\"rated-user user-orange\">Smit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 16:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145885\" href=\"?#comment-145885\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145868\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145885\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"19252\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145885\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>solution: <a href=\"//codeforces.com/contest/342/submission/4424666\">http://codeforces.com/contest/342/submission/4424666</a></p><p>it does not matter whether it was vertical block or 2 horizontal block. (i,3) tells that all the blocks in first i-1 columns are filled and in this column there is only last row left to be filled.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145885 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145885 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145885\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145656\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rhd\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78747/avatar/b4494f9b3e154714.jpg'/> </a>\n <div><a href=\"/profile/rhd\" title=\"Unrated, rhd\" class=\"rated-user user-black\">rhd</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2013 04:45\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145656\" href=\"?#comment-145656\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145656\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145656\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78747\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145656\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>.d.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145656 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145656 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145656\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145671\" commentParentId=\"145656\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Qubit01\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1399/avatar/c963814250395100.jpg'/> </a>\n <div><a href=\"/profile/Qubit01\" title=\"Expert Qubit01\" class=\"rated-user user-blue\">Qubit01</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2013 12:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145671\" href=\"?#comment-145671\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145656\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145671\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1399\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145671\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Assume that you have the distances from vertex with index <em>1</em> to every vertex <em>u</em> in a vector <em>d[]</em>.</p><p>Define <em>lca(x, y)</em> the lowest common ancestor for vertex <em>x</em> and <em>y</em>. You must find out the distance from <em>v</em> to <em>u</em>. </p><p>The result is <em>d[u] + d[v] — 2 * lca(u, v)</em> because you add twice the distance from vertex <em>1</em> to <em>lca(u, v)</em> (that's where the 2 roads intersects). You can draw a tree on a paper and and work with some examples, it will be clearer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145671 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145671 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145671\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146192\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lkjslkjdlk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34453/avatar/944f96e876fade4b.jpg'/> </a>\n <div><a href=\"/profile/lkjslkjdlk\" title=\"Specialist lkjslkjdlk\" class=\"rated-user user-cyan\">lkjslkjdlk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 14:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146192\" href=\"?#comment-146192\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146192\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34453\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146192\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could you please tell me the complexity of the Problem E?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146192 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146192 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146192\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146196\" commentParentId=\"146192\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lkjslkjdlk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34453/avatar/944f96e876fade4b.jpg'/> </a>\n <div><a href=\"/profile/lkjslkjdlk\" title=\"Specialist lkjslkjdlk\" class=\"rated-user user-cyan\">lkjslkjdlk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 16:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146196\" href=\"?#comment-146196\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146192\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146196\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34453\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146196\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here is my solution: <a href=\"//codeforces.com/contest/342/submission/4509629\">http://codeforces.com/contest/342/submission/4509629</a> The complexity seems to be O((n+m)*sqrt(m)). But it still gets TLE.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146196 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146196 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146196\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"458577\" commentParentId=\"146196\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mahagoni\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/567134/avatar/f60a9c806d357d9e.jpg'/> </a>\n <div><a href=\"/profile/Mahagoni\" title=\"Expert Mahagoni\" class=\"rated-user user-blue\">Mahagoni</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2018 00:21\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-458577\" href=\"?#comment-458577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146196\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"458577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"567134\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-458577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><em>O(n*sqrt(m)*log(n))</em></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-458577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-458577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-458577\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"673071\" commentParentId=\"146192\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/muzzaleeni\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/621091/avatar/e6a7f915e328dcd8.jpg'/> </a>\n <div><a href=\"/profile/muzzaleeni\" title=\"Pupil muzzaleeni\" class=\"rated-user user-green\">muzzaleeni</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/02/2020 11:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-673071\" href=\"?#comment-673071\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146192\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"673071\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"621091\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-673071\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>\\begin{equation}m \\cdot\\sqrt{m}\\cdot\\log_2{(n)}\\end{equation}</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-673071 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-673071 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-673071\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"937837\" commentParentId=\"673071\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Phantom_Performer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1746799/avatar/bc1dcacc56722125.jpg'/> </a>\n <div><a href=\"/profile/Phantom_Performer\" title=\"Master Phantom_Performer\" class=\"rated-user user-orange\">Phantom_Performer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/30/2022 17:45\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-937837\" href=\"?#comment-937837\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-673071\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"937837\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1746799\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-937837\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can precalculate the lca of nodes in Mlogn</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-937837 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-937837 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-937837\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"156861\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Harun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48372/avatar/15bf49d98279c433.jpg'/> </a>\n <div><a href=\"/profile/Harun\" title=\"Expert Harun\" class=\"rated-user user-blue\">Harun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/05/2014 22:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-156861\" href=\"?#comment-156861\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"156861\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48372\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-156861\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In E problem , there isn't any boundary case like chain. Then O(N*N) solution can get AC.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-156861 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-156861 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-156861\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"545136\" commentParentId=\"156861\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SevenDeadlySins\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/430874/avatar/b011182bef4f60f0.jpg'/> </a>\n <div><a href=\"/profile/SevenDeadlySins\" title=\"Pupil SevenDeadlySins\" class=\"rated-user user-green\">SevenDeadlySins</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2019 13:59\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-545136\" href=\"?#comment-545136\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-156861\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"545136\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"430874\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-545136\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>did u code in cpp?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-545136 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-545136 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-545136\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"545137\" commentParentId=\"545136\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Harun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48372/avatar/15bf49d98279c433.jpg'/> </a>\n <div><a href=\"/profile/Harun\" title=\"Expert Harun\" class=\"rated-user user-blue\">Harun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2019 14:04\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-545137\" href=\"?#comment-545137\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-545136\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"545137\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48372\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-545137\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don’t even remember what I had for dinner last night and you’re here asking me about a code I wrote 6 years ago. That’s like a lot of months :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-545137 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-545137 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-545137\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"545138\" commentParentId=\"545137\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SevenDeadlySins\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/430874/avatar/b011182bef4f60f0.jpg'/> </a>\n <div><a href=\"/profile/SevenDeadlySins\" title=\"Pupil SevenDeadlySins\" class=\"rated-user user-green\">SevenDeadlySins</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2019 14:09\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-545138\" href=\"?#comment-545138\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-545137\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"545138\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"430874\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-545138\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>That can be answered with what language u used to code with... But anyway you have a point... and I got the ans after stalking your profile... Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-545138 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-545138 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-545138\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"174599\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dtalamas24\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60129/avatar/200478a7b9850d4b.jpg'/> </a>\n <div><a href=\"/profile/dtalamas24\" title=\"Candidate Master dtalamas24\" class=\"rated-user user-violet\">dtalamas24</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2014 09:33\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-174599\" href=\"?#comment-174599\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"174599\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"174599\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60129\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-174599\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Any online solutions for problem E ? Or different solutions to E?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-174599 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-174599 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-174599\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176403\" commentParentId=\"174599\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kllp\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/100053/avatar/44882b58f6756412.jpg'/> </a>\n <div><a href=\"/profile/kllp\" title=\"Master kllp\" class=\"rated-user user-orange\">kllp</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/02/2014 23:38\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176403\" href=\"?#comment-176403\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-174599\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"176403\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"100053\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176403\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My solution uses Heavy-light decomposition and segment trees. Complexity is O(N log^2 N). <a href=\"//codeforces.com/contest/342/submission/6999318\">http://codeforces.com/contest/342/submission/6999318</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176403 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176403 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176403\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"181789\" commentParentId=\"176403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Harun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48372/avatar/15bf49d98279c433.jpg'/> </a>\n <div><a href=\"/profile/Harun\" title=\"Expert Harun\" class=\"rated-user user-blue\">Harun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/09/2014 17:53\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-181789\" href=\"?#comment-181789\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"181789\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48372\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-181789\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could you explain your idea ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-181789 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-181789 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-181789\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"252934\" commentParentId=\"176403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/manmodeashish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/manmodeashish\" title=\"Specialist manmodeashish\" class=\"rated-user user-cyan\">manmodeashish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/28/2015 12:33\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-252934\" href=\"?#comment-252934\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"252934\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"226988\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-252934\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>very good. It was really helpful. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-252934 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-252934 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-252934\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"442050\" commentParentId=\"176403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cai_lw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/325977/avatar/202b61935928944.jpg'/> </a>\n <div><a href=\"/profile/cai_lw\" title=\"International Master cai_lw\" class=\"rated-user user-orange\">cai_lw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/02/2018 17:36\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-442050\" href=\"?#comment-442050\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"442050\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"325977\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-442050\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We can achieve O(NlogN) if we store each "heavy chains" in separate segment trees. For each operation, all queries and updates, except the beginning one, are on the whole chain, and only takes O(1). Therefore, each operation takes O(logN)*O(1)+O(1)*O(logN)=O(logN)</p><p><a href=\"//codeforces.com/contest/342/submission/39871066\">My solution</a> (it doesn't run faster in practice though)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-442050 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-442050 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-442050\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"213929\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mindbeats\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/56717/avatar/bcddf2e5600931f3.jpg'/> </a>\n <div><a href=\"/profile/mindbeats\" title=\"Expert mindbeats\" class=\"rated-user user-blue\">mindbeats</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2015 00:14\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-213929\" href=\"?#comment-213929\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"213929\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"56717\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-213929\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in problem E, the complexity is O(N * sqrtN * logN).... logN because of the LCA part it doesn't pass the time</p><p>how did you handle this !!?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-213929 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-213929 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-213929\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"937838\" commentParentId=\"213929\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Phantom_Performer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1746799/avatar/bc1dcacc56722125.jpg'/> </a>\n <div><a href=\"/profile/Phantom_Performer\" title=\"Master Phantom_Performer\" class=\"rated-user user-orange\">Phantom_Performer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/30/2022 17:45\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-937838\" href=\"?#comment-937838\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-213929\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"937838\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1746799\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-937838\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can precalculate the lca of nodes in Mlogn</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-937838 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-937838 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-937838\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"937911\" commentParentId=\"937838\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mindbeats\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/56717/avatar/bcddf2e5600931f3.jpg'/> </a>\n <div><a href=\"/profile/mindbeats\" title=\"Expert mindbeats\" class=\"rated-user user-blue\">mindbeats</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/31/2022 05:01\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-937911\" href=\"?#comment-937911\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-937838\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"937911\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"56717\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-937911\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>oh 7 years to get an answer...that was really too fast! :D </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-937911 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-937911 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-937911\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"316277\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2016 18:20\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-316277\" href=\"?#comment-316277\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"316277\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"316277\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-316277\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Deleted</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-316277 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-316277 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-316277\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"335462\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/....\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/....\" title=\"Expert ....\" class=\"rated-user user-blue\">....</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/04/2017 21:36\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-335462\" href=\"?#comment-335462\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"335462\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"335462\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"490997\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-335462\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem <a href=\"/contest/342/problem/E\" title=\"Codeforces Round 199 (Div. 2)\">342E - Xenia and Tree</a>, I came across a centroid decomposition solution <a href=\"/contest/342/submission/23224047\" title=\"Submission 23224047 by raiden_11\">23224047</a>. I have gone through the solution, but I am not able to convince myself about the correctness of the algorithm and the reason as to why query method is correct(or works). Please help!</p><p>PS: <a class=\"rated-user user-violet\" href=\"/profile/HolkinPV\" title=\"Candidate Master HolkinPV\">HolkinPV</a>, can you please help?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-335462 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-335462 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-335462\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"528302\" commentParentId=\"335462\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/VLADO\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/630234/avatar/e6872ed793f74338.jpg'/> </a>\n <div><a href=\"/profile/VLADO\" title=\"Expert VLADO\" class=\"rated-user user-blue\">VLADO</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/19/2019 15:37\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-528302\" href=\"?#comment-528302\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-335462\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"528302\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"630234\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-528302\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm a bit late but the solution is explained <a href=\"https://threads-iiith.quora.com/Centroid-Decomposition-of-a-Tree\">here</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-528302 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-528302 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-528302\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"370331\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/S.Jindal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/508955/avatar/43cfebadfb0dea2c.jpg'/> </a>\n <div><a href=\"/profile/S.Jindal\" title=\"Candidate Master S.Jindal\" class=\"rated-user user-violet\">S.Jindal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/29/2017 07:28\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-370331\" href=\"?#comment-370331\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"370331\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"508955\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-370331\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve Div1,C if we have to return the maximum distance to any red node instead of min distance...?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-370331 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-370331 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-370331\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371401\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nitesh_gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/454345/avatar/88dd212e02074fb0.jpg'/> </a>\n <div><a href=\"/profile/nitesh_gupta\" title=\"Master nitesh_gupta\" class=\"rated-user user-orange\">nitesh_gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/03/2017 11:52\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371401\" href=\"?#comment-371401\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"371401\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"371401\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"454345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371401\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"Distance between two nodes dist(u, v) can be got using preprocessing for lca." - Xenia and Tree</p><p>Can anyone explain me how to do it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371401 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371401 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371401\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371545\" commentParentId=\"371401\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MasT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/451310/avatar/10587ffa9ae01331.jpg'/> </a>\n <div><a href=\"/profile/MasT\" title=\"Expert MasT\" class=\"rated-user user-blue\">MasT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2017 07:00\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371545\" href=\"?#comment-371545\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371401\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"371545\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"371545\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"451310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371545\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Notice that <code>dist(u, v) = dist(root, u) + dist(root, v) - 2 * dist(root, l)</code>, where l is the LCA of u and v</p><p>1) Use a DFS to find the distance from node 1 (the root) to every other node. Let <code>rootDist[n]</code> by the distance from node 1 to node n. The DFS should also find the parent of each node, and the depth of each node from the root. Let <code>parent[n]</code> be the parent of node n and <code>depth[n]</code> be the depth of node n.</p><p>Example DFS code:</p> <pre><code>//Let MAX be the number of maximum nodes\nvector<int> adj[MAX];\nint rootDist[MAX], parent[MAX], depth[MAX];\n\n// cur = Current traversing node\n// prev = Node traversed before this one\nint dfs(int cur, int prev){\n parent[cur] = prev;\n\n for(int child : adj[cur]){\n if(child != prev){\n depth[child] = depth[cur] + 1;\n rootDist[child] = rootDist[cur] + 1;\n // Note: In the case of an unweighted tree,\n // depth[n] == rootDist[n]\n\n dfs(child, cur);\n\n }\n }\n}\n\ndfs(1, -1);\n</code></pre><p>2) Build a sparse table. <code>sparse[u][i]</code> stores the 2**i-th parent of u, or <code>-1</code> if that parent doesn't exist. Note that <code>sparse[u][0] = parent[n]</code>. The sparse table can be built by:</p> <pre><code>// N = number of nodes as given in input\n// LN = ceil(log2(Max number of nodes))\n// Using 1-indexing for nodes\nint sparse[MAX][LN];\nmemset(sparse, -1, sizeof sparse);\n\nfor(int u = 1; u <= N; u++)\n sparse[u][0] = parent[u];\n\nfor(int i = 1; i < LN; i++)\n for(int u = 1; u <= N; u++)\n //if the node has a 2**(i - 1)th parent\n if(sparse[u][i - 1] != -1)\n // the 2**i-th parent of u is equal to\n // the 2**(i - 1)th parent of 2**(i - 1)th parent of u\n sparse[u][i] = sparse [ sparse[u][i - 1] ] [i - 1];\n</code></pre><p>3) To query the lca of u and v, we do the following steps:</p> <ol> <li>If u has a smaller depth than v, swap them</li> <li>Find the ancestor of u with the same depth of v</li> <li>If u and v are the same node, return it</li> <li>Find the highest (least depth) ancestor of u and v (let's call them u' and v') such that u' is not v'</li> <li>Return the parent of u' (which is equal to the parent of v')</li> </ol><p>Here is the code for the query:</p> <pre><code>int lca(int u, int v){\n if(depth[u] < depth[v])\n swap(u, v);\n\n // We use sparse table so we jump 2**i parents each time\n // Taking only log time\n for(int i = LN - 1; i >= 0; i--)\n // If the 2**i-th parent of u isn't higher than v\n if(depth[ sparse[u][i] ] >= depth[v])\n // Go up 2**i parents\n u = sparse[u][i];\n\n // At this point, depth[u] == depth[v]\n // If they happen to be the same node, that is the LCA\n if(u == v)\n return u;\n\n for(int i = LN - 1; i >= 0; i--){\n // If their ancestors aren't the same\n if(sparse[u][i] != sparse[v][i]){\n // Go up to their ancestor\n u = sparse[u][i];\n v = sparse[v][i];\n }\n }\n\n // At this point, they're at the highest ancestor\n // such that they're not the same, so one parent above\n // must be their LCA\n\n // 2**0 = 1, return first parent of u\n return sparse[u][0];\n // this is also equal to sparse[v][0]\n}\n</code></pre><p>And finally, to put it all together, to query distance</p> <pre><code>int dist(int u, int v){\n int l = lca(u, v);\n return rootDist[u] + rootDist[v] - 2 * rootDist[l];\n}\n</code></pre><p>Building the LCA sparse table takes <code>O(n log n)</code> time while querying takes <code>O(log n)</code> time</p><p>(I wrote this from memory; please tell me if there are any mistakes or if any part is confusing)</p><p><a href=\"https://www.topcoder.com/community/data-science/data-science-tutorials/range-minimum-query-and-lowest-common-ancestor/\">Source/Additional reading</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371545 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371545 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371545\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371617\" commentParentId=\"371545\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nitesh_gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/454345/avatar/88dd212e02074fb0.jpg'/> </a>\n <div><a href=\"/profile/nitesh_gupta\" title=\"Master nitesh_gupta\" class=\"rated-user user-orange\">nitesh_gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2017 20:32\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371617\" href=\"?#comment-371617\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371545\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"371617\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"454345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371617\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for your help. You explained very well.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371617 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371617 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371617\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"425765\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sonupmandal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/356694/avatar/a3df14f7c5265075.jpg'/> </a>\n <div><a href=\"/profile/sonupmandal\" title=\"Pupil sonupmandal\" class=\"rated-user user-green\">sonupmandal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/18/2018 07:38\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-425765\" href=\"?#comment-425765\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"425765\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"356694\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-425765\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to do this - Calculate minimum distances from every node to the closest red node using bfs.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-425765 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-425765 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-425765\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"432106\" commentParentId=\"425765\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kayak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/700181/avatar/ec3f04c38ba70bde.jpg'/> </a>\n <div><a href=\"/profile/kayak\" title=\"Expert kayak\" class=\"rated-user user-blue\">kayak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2018 18:49\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-432106\" href=\"?#comment-432106\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-425765\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"432106\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"432106\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"700181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-432106\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Store all nodes which are currently red in a vector redlist. Create an queue bfslist for bfs, and create a array <code>dist[v] = Distance from v to the nearest red node, 0 if v is itself red</code> and initialize an empty queue. Now for all red vertices <span class=\"tex-span\"><i>v</i></span>, let <code>dist[v] = 0</code> and push all the neighbours <span class=\"tex-span\"><i>u</i></span> of the red vertices which are not red into this queue, and for all such <span class=\"tex-span\"><i>u</i></span>, let <code>dist[u] = 1, isdiscovered[u] = 1</code>. Now it's just regular bfs: while the queue is nonempty, pop the first element <code>w</code> from the queue, and add all the neighbours <code>y</code> of <code>w</code> not already discovered to the queue, and let <code>dist[y] = dist[w] +1, isdiscovered[y] = 1</code>. Here's a code implementing it:</p> <pre><code>void bfs(){\n std::queue<int> bfslist;\n int isdisc[N] = {0};\n for (int i = 0; i < red.size(); i +=1){\n int a = red[i];\n reddist[a] = 0;\n isdisc[i] = 1;\n for (int j = 0; j < adjlist[a].size(); j +=1){\n int b = adjlist[a][j];\n if ((isred[b] == 1) && (isdisc[b] == 0)){\n bfslist.push(b);\n reddist[b] = 1;\n isdisc[b] = 1;\n }\n }\n }\n while (!bfslist.empty()){\n int a = bfslist.front();\n bfslist.pop();\n for (int i = 0; i < adjlist[a].size(); i +=1){\n int b = adjlist[a][i];\n if ((isred[b] ==1) && (isdisc[b] == 0)){\n bfslist.push(b);\n reddist[b] = reddist[a]+1;\n isdisc[b] = 1;\n }\n }\n }\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-432106 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-432106 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-432106\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"446034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arjitkansal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/542324/avatar/cb05cf6d94faff9c.jpg'/> </a>\n <div><a href=\"/profile/arjitkansal\" title=\"Master arjitkansal\" class=\"rated-user user-orange\">arjitkansal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/18/2018 09:51\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-446034\" href=\"?#comment-446034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"446034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"542324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-446034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, can anyone please help me debug this code for Problem E. </p><p><a href=\"https://codeforces.com/contest/342/submission/39819558\">https://codeforces.com/contest/342/submission/39819558</a></p><p>It has been days and I've not been able to find the error.</p><p>I used 'Centroid Decomposition'.</p><p>Thanks in Advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-446034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-446034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-446034\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"566831\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ac_97\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1211001/avatar/6e08c927b196de27.jpg'/> </a>\n <div><a href=\"/profile/ac_97\" title=\"Specialist ac_97\" class=\"rated-user user-cyan\">ac_97</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/24/2019 00:32\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-566831\" href=\"?#comment-566831\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"566831\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1211001\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-566831\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem Div2 E, can someone share the code implementing the sqrt optimization trick. Are there any resources for this technique ? In what all cases can this technique be applied ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-566831 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-566831 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-566831\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"598414\" commentParentId=\"566831\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Skeef79\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631759/avatar/3033511aaec49179.jpg'/> </a>\n <div><a href=\"/profile/Skeef79\" title=\"Candidate Master Skeef79\" class=\"rated-user user-violet\">Skeef79</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/06/2020 13:06\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-598414\" href=\"?#comment-598414\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-566831\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"598414\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"631759\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-598414\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://pastebin.com/cCYBLvjs\">https://pastebin.com/cCYBLvjs</a></p><p><a href=\"https://codeforces.com/contest/342/submission/75643716\">https://codeforces.com/contest/342/submission/75643716</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-598414 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-598414 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-598414\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"584071\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mooncrater\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/656776/avatar/d19b34b1e226e4ad.jpg'/> </a>\n <div><a href=\"/profile/Mooncrater\" title=\"Specialist Mooncrater\" class=\"rated-user user-cyan\">Mooncrater</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/26/2020 20:31\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-584071\" href=\"?#comment-584071\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"584071\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"656776\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-584071\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div2 C, what comments?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-584071 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-584071 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-584071\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"913528\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mynameisminh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/mynameisminh\" title=\"Newbie mynameisminh\" class=\"rated-user user-gray\">mynameisminh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2022 19:24\">17 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-913528\" href=\"?#comment-913528\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"913528\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2253580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-913528\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can somebody help me with problems 342E. Here's my source code: <a href=\"https://codeforces.com/problemset/submission/342/157723527\">https://codeforces.com/problemset/submission/342/157723527</a></p><p>I still don't know why I got TLE. Thanks so much!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-913528 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-913528 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-913528\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"924618\" commentParentId=\"913528\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lite_27\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2584952/avatar/d7812158a0f2af9b.jpg'/> </a>\n <div><a href=\"/profile/lite_27\" title=\"Specialist lite_27\" class=\"rated-user user-cyan\">lite_27</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2022 23:07\">16 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-924618\" href=\"?#comment-924618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-913528\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"924618\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"924618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2584952\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-924618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-924618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-924618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-924618\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8871\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8871 = true;\r\nvar lastPreviewContent8871 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8871] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8871] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8855\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8855, _tta: Codeforces.tta(), topicRevisionId: 31374, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8855\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8855, _tta: Codeforces.tta(), topicRevisionId: 31374, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:21</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'81287486695d9d99',t:'MTY5NjcwNTk0MS43NDgwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1736,"cells":{"problem_id":{"kind":"string","value":"342E"},"contest":{"kind":"string","value":"342"},"problem":{"kind":"string","value":"E"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"E. Xenia and Tree"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Xenia and Tree</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>5 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Xenia the programmer has a tree consisting of <span class=\"tex-span\"><i>n</i></span> nodes. We will consider the tree nodes indexed from 1 to <span class=\"tex-span\"><i>n</i></span>. We will also consider the first node to be initially painted red, and the other nodes — to be painted blue.</p><p>The <span class=\"tex-font-style-it\">distance</span> between two tree nodes <span class=\"tex-span\"><i>v</i></span> and <span class=\"tex-span\"><i>u</i></span> is the number of edges in the shortest path between <span class=\"tex-span\"><i>v</i></span> and <span class=\"tex-span\"><i>u</i></span>.</p><p>Xenia needs to learn how to quickly execute queries of two types:</p><ol> <li> paint a specified blue node in red; </li><li> calculate which red node is the closest to the given one and print the shortest distance to the closest red node. </li></ol><p>Your task is to write a program which will execute the described queries.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(2 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>, 1 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span> — the number of nodes in the tree and the number of queries. Next <span class=\"tex-span\"><i>n</i> - 1</span> lines contain the tree edges, the <span class=\"tex-span\"><i>i</i></span>-th line contains a pair of integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>, <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub>)</span> — an edge of the tree.</p><p>Next <span class=\"tex-span\"><i>m</i></span> lines contain queries. Each query is specified as a pair of integers <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub>, <i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>t</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 2, 1 ≤ <i>v</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>)</span>. If <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub> = 1</span>, then as a reply to the query we need to paint a blue node <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> in red. If <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub> = 2</span>, then we should reply to the query by printing the shortest distance from some red node to node <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>It is guaranteed that the given graph is a tree and that all queries are correct.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each second type query print the reply in a single line.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 4<br/>1 2<br/>2 3<br/>2 4<br/>4 5<br/>2 1<br/>2 5<br/>1 2<br/>2 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/>3<br/>2<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"783f99780f238425f48edeac3b57117c\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"91a1e137bf92bd9ed30f9398e9597722ab5e17d3\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='783f99780f238425f48edeac3b57117c'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F342%2Fproblem%2FE%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='783f99780f238425f48edeac3b57117c'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/342\">Codeforces Round 199 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='783f99780f238425f48edeac3b57117c'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/342/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Heaps, binary search trees, segment trees, hash tables, etc\">\r\n data structures\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Divide and Conquer\">\r\n divide and conquer\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Trees\">\r\n trees\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2400\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='783f99780f238425f48edeac3b57117c'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3442\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='783f99780f238425f48edeac3b57117c'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3442\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8795\" title=\"Codeforces Round #199 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1837:1838\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/8800\" title=\"Tutorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1840\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/342\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/342/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/342/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/342/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/342/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/342/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/342/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/342/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_d341e91b9f294af9a687ff5cae15e89c30df265e\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Xenia and Tree</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>5 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Xenia the programmer has a tree consisting of <span class=\"tex-span\"><i>n</i></span> nodes. We will consider the tree nodes indexed from 1 to <span class=\"tex-span\"><i>n</i></span>. We will also consider the first node to be initially painted red, and the other nodes — to be painted blue.</p><p>The <span class=\"tex-font-style-it\">distance</span> between two tree nodes <span class=\"tex-span\"><i>v</i></span> and <span class=\"tex-span\"><i>u</i></span> is the number of edges in the shortest path between <span class=\"tex-span\"><i>v</i></span> and <span class=\"tex-span\"><i>u</i></span>.</p><p>Xenia needs to learn how to quickly execute queries of two types:</p><ol> <li> paint a specified blue node in red; </li><li> calculate which red node is the closest to the given one and print the shortest distance to the closest red node. </li></ol><p>Your task is to write a program which will execute the described queries.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(2 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>, 1 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span> — the number of nodes in the tree and the number of queries. Next <span class=\"tex-span\"><i>n</i> - 1</span> lines contain the tree edges, the <span class=\"tex-span\"><i>i</i></span>-th line contains a pair of integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>, <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub>)</span> — an edge of the tree.</p><p>Next <span class=\"tex-span\"><i>m</i></span> lines contain queries. Each query is specified as a pair of integers <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub>, <i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>t</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 2, 1 ≤ <i>v</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>)</span>. If <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub> = 1</span>, then as a reply to the query we need to paint a blue node <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> in red. If <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub> = 2</span>, then we should reply to the query by printing the shortest distance from some red node to node <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>It is guaranteed that the given graph is a tree and that all queries are correct.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each second type query print the reply in a single line.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 4<br />1 2<br />2 3<br />2 4<br />4 5<br />2 1<br />2 5<br />1 2<br />2 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br />3<br />2<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:32</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bd676e1f4989',t:'MTY5NjY0NjAxMi4xNDEwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Heaps, binary search trees, segment trees, hash tables, etc\", \"Divide and Conquer\", \"Trees\"]"},"short_tags":{"kind":"string","value":"[\"data structures\", \"divide and conquer\", \"trees\", \"*2400\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8800"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"779401b049eaea220649756fcc29cd29\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #199 (Div. 2) Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #199 (Div. 2) Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='779401b049eaea220649756fcc29cd29'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8800\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='779401b049eaea220649756fcc29cd29'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:41</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:41</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='779401b049eaea220649756fcc29cd29'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/HolkinPV\">HolkinPV</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/HolkinPV\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/HolkinPV\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/HolkinPV\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/HolkinPV\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/HolkinPV\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/HolkinPV\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/HolkinPV\" style=\"text-decoration:none;color:black !important;\">HolkinPV's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8855\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8800\"> <p>Codeforces Round #199 (Div. 2) Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/HolkinPV\" title=\"Candidate Master HolkinPV\" class=\"rated-user user-violet\">HolkinPV</a>,\r\n <span class=\"format-humantime\" title=\"Sep/07/2013 14:37\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/342/problem/A\" title=\"Codeforces Round 199 (Div. 2)\">342A - Xenia and Divisors</a></p><p>In this problem you should guess that exists only three valid groups of three </p><p>1) 1, 2, 4 </p><p>2) 1, 2, 6 </p><p>3) 1, 3, 6 </p><p>(You can see that integers 5 and 7 are bad).</p><p>So, we will greedy take these groups of three. If some integers will be not used, the answer is -1. In other case, print found answer.</p><p><a href=\"/contest/342/problem/B\" title=\"Codeforces Round 199 (Div. 2)\">342B - Xenia and Spies</a></p><p>The problem is solved by greedy algorithm. We will pass the note only in correct direction. Also, if we can pass the note at the current moment of time, we do it. In other case, we will hold it and don't give it to neighbors (we can make this action at any moment of time). Obviously this algorithm is correct. You should only implement it carefully.</p><p><a href=\"/contest/342/problem/C\" title=\"Codeforces Round 199 (Div. 2)\">342C - Cupboard and Balloons</a></p><p>In the problem you should carefully get formula. The optimal solution put marbles by two in a row. And then put one marble upon others if it possible. The most difficulties were to deal with this last phase. </p><p>In comments to the post were given formulas how to put the last marble (exactly in the middle). And there was a good beautiful illustration, which describes the situation.</p><p><a href=\"/contest/342/problem/D\" title=\"Codeforces Round 199 (Div. 2)\">342D - Xenia and Dominoes</a></p><p>In the problem you can count number of correct puzzles or substract number of incorrect puzzles from number of all puzzles. In any case you should count DP, where the state is <span class=\"tex-span\">(<i>j</i>, <i>mask</i>)</span> — <span class=\"tex-span\"><i>j</i></span> — number of the last full column, <span class=\"tex-span\"><i>mask</i></span> — mask of the last column. This problem is equivalent to the well known problem about domino tiling or the problem about parquet.</p><p>To get the solution of the whole problem I did the following. I try to attach one domino to each of 4 directions, then paint all three cells in black and count the number of correct puzzles. But in this case you will count some solutions several number of times. So you need to use inclusion exclusion formula for these 4 directions.</p><p><a href=\"/contest/342/problem/E\" title=\"Codeforces Round 199 (Div. 2)\">342E - Xenia and Tree</a></p><p>The problem can be solved in different ways. The most easy idea is sqrt-optimization. Split all queries into <span class=\"tex-span\"><i>sqrt</i>(<i>m</i>)</span> blocks. Each block we will process separately. Before processing each block, we should calculate minimum distances from every node to the closest red node using bfs. To answer the query we should update this value by shortest distances to red nodes in current block.</p><p>The solution becomes simple. Every <span class=\"tex-span\"><i>sqrt</i>(<i>m</i>)</span> queries we make simple bfs and for every node <span class=\"tex-span\"><i>v</i></span> WE calculate value <span class=\"tex-span\"><i>d</i>[<i>v</i>]</span> — the shortest distance to some red node from node <span class=\"tex-span\"><i>v</i></span>. Then to answer the query of type 2 you should calculate <span class=\"tex-span\"><i>min</i>(<i>d</i>[<i>v</i>], <i>dist</i>(<i>v</i>, <i>u</i>))</span>, where <span class=\"tex-span\"><i>u</i></span> — every red node, which becomes red in current block of length <span class=\"tex-span\"><i>sqrt</i>(<i>m</i>)</span>.</p><p>Distance between two nodes <span class=\"tex-span\"><i>dist</i>(<i>u</i>, <i>v</i>)</span> can be got using preprocessing for lca.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/342\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 199 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-230-8855\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"230\",\n blogEntryId: \"8800\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=199\" class=\"tag notice\" style=\"text-decoration: none;\">199</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8855\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+38</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8855\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/HolkinPV\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/HolkinPV\">\n HolkinPV\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/07/2013 14:37\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8800#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8800#comments\">\n 43\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8871\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (38)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145322\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/10/2013 19:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145322\" href=\"?#comment-145322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain problem D in more detail, I am not able to understand anything from what is posted. </p><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145322\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145419\" commentParentId=\"145322\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Smit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/19252/avatar/d7815c7f59ae1a65.jpg'/> </a>\n <div><a href=\"/profile/Smit\" title=\"Master Smit\" class=\"rated-user user-orange\">Smit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/12/2013 02:41\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145419\" href=\"?#comment-145419\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145322\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145419\" revisionCount=\"5\" revision=\"5\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">5</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145419\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"19252\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145419\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Solution is simple. let me explain it with a examples:</p><p>suppose we have filled all the empty blocks from column 0....i-1 and on ith column we have filled some of the empty blocks which is stored using mask 0,1,...,7</p><p>suppose if mask is currently 0 and i=2, so configuration could be something like this.</p> <pre><code>AA.X.\nAA.0.\nAA.X.\n</code></pre><p>blocks with A are already filled.</p><p>now we have two options, we might use some vertical block or not:</p> <pre><code>1. if we use vertical block and put it in first 2 rows. new state ----> (i,3)\n2. if we use vertical block and put it in last 2 rows. new state ----> (i,6)\n3. if we choose not to use vertical block we have to use 3 horizontal one ----> (i+1,7)\n</code></pre><p>now we are almost ready with solution and need to check while putting block if that box was empty earlier and which we put block near 0, we need to note this also.</p><p>I think, you should be able to understand my code now.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145419 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145419 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145419\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145868\" commentParentId=\"145419\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 14:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145868\" href=\"?#comment-145868\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145419\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145868\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145868\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could you please post the link to your solution.</p><p>I got the algorithm but I am lacking clarity over some points like considering the state (i,3), How does one keep track of whether a single vertical block was placed or 2 horizontal blocks covering the squares were placed.</p><p>Anyways, thanks for your explanation.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145868 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145868 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145868\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145885\" commentParentId=\"145868\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Smit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/19252/avatar/d7815c7f59ae1a65.jpg'/> </a>\n <div><a href=\"/profile/Smit\" title=\"Master Smit\" class=\"rated-user user-orange\">Smit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 16:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145885\" href=\"?#comment-145885\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145868\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145885\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"19252\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145885\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>solution: <a href=\"//codeforces.com/contest/342/submission/4424666\">http://codeforces.com/contest/342/submission/4424666</a></p><p>it does not matter whether it was vertical block or 2 horizontal block. (i,3) tells that all the blocks in first i-1 columns are filled and in this column there is only last row left to be filled.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145885 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145885 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145885\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145656\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rhd\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78747/avatar/b4494f9b3e154714.jpg'/> </a>\n <div><a href=\"/profile/rhd\" title=\"Unrated, rhd\" class=\"rated-user user-black\">rhd</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2013 04:45\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145656\" href=\"?#comment-145656\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"145656\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"145656\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78747\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145656\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>.d.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145656 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145656 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145656\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145671\" commentParentId=\"145656\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Qubit01\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1399/avatar/c963814250395100.jpg'/> </a>\n <div><a href=\"/profile/Qubit01\" title=\"Expert Qubit01\" class=\"rated-user user-blue\">Qubit01</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2013 12:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145671\" href=\"?#comment-145671\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145656\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145671\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1399\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145671\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Assume that you have the distances from vertex with index <em>1</em> to every vertex <em>u</em> in a vector <em>d[]</em>.</p><p>Define <em>lca(x, y)</em> the lowest common ancestor for vertex <em>x</em> and <em>y</em>. You must find out the distance from <em>v</em> to <em>u</em>. </p><p>The result is <em>d[u] + d[v] — 2 * lca(u, v)</em> because you add twice the distance from vertex <em>1</em> to <em>lca(u, v)</em> (that's where the 2 roads intersects). You can draw a tree on a paper and and work with some examples, it will be clearer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145671 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145671 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145671\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146192\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lkjslkjdlk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34453/avatar/944f96e876fade4b.jpg'/> </a>\n <div><a href=\"/profile/lkjslkjdlk\" title=\"Specialist lkjslkjdlk\" class=\"rated-user user-cyan\">lkjslkjdlk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 14:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146192\" href=\"?#comment-146192\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146192\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34453\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146192\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could you please tell me the complexity of the Problem E?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146192 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146192 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146192\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146196\" commentParentId=\"146192\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lkjslkjdlk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34453/avatar/944f96e876fade4b.jpg'/> </a>\n <div><a href=\"/profile/lkjslkjdlk\" title=\"Specialist lkjslkjdlk\" class=\"rated-user user-cyan\">lkjslkjdlk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 16:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146196\" href=\"?#comment-146196\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146192\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146196\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34453\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146196\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here is my solution: <a href=\"//codeforces.com/contest/342/submission/4509629\">http://codeforces.com/contest/342/submission/4509629</a> The complexity seems to be O((n+m)*sqrt(m)). But it still gets TLE.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146196 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146196 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146196\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"458577\" commentParentId=\"146196\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mahagoni\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/567134/avatar/f60a9c806d357d9e.jpg'/> </a>\n <div><a href=\"/profile/Mahagoni\" title=\"Expert Mahagoni\" class=\"rated-user user-blue\">Mahagoni</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2018 00:21\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-458577\" href=\"?#comment-458577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146196\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"458577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"567134\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-458577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><em>O(n*sqrt(m)*log(n))</em></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-458577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-458577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-458577\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"673071\" commentParentId=\"146192\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/muzzaleeni\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/621091/avatar/e6a7f915e328dcd8.jpg'/> </a>\n <div><a href=\"/profile/muzzaleeni\" title=\"Pupil muzzaleeni\" class=\"rated-user user-green\">muzzaleeni</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/02/2020 11:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-673071\" href=\"?#comment-673071\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146192\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"673071\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"621091\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-673071\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>\\begin{equation}m \\cdot\\sqrt{m}\\cdot\\log_2{(n)}\\end{equation}</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-673071 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-673071 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-673071\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"937837\" commentParentId=\"673071\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Phantom_Performer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1746799/avatar/bc1dcacc56722125.jpg'/> </a>\n <div><a href=\"/profile/Phantom_Performer\" title=\"Master Phantom_Performer\" class=\"rated-user user-orange\">Phantom_Performer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/30/2022 17:45\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-937837\" href=\"?#comment-937837\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-673071\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"937837\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1746799\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-937837\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can precalculate the lca of nodes in Mlogn</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-937837 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-937837 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-937837\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"156861\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Harun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48372/avatar/15bf49d98279c433.jpg'/> </a>\n <div><a href=\"/profile/Harun\" title=\"Expert Harun\" class=\"rated-user user-blue\">Harun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/05/2014 22:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-156861\" href=\"?#comment-156861\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"156861\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48372\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-156861\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In E problem , there isn't any boundary case like chain. Then O(N*N) solution can get AC.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-156861 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-156861 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-156861\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"545136\" commentParentId=\"156861\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SevenDeadlySins\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/430874/avatar/b011182bef4f60f0.jpg'/> </a>\n <div><a href=\"/profile/SevenDeadlySins\" title=\"Pupil SevenDeadlySins\" class=\"rated-user user-green\">SevenDeadlySins</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2019 13:59\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-545136\" href=\"?#comment-545136\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-156861\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"545136\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"430874\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-545136\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>did u code in cpp?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-545136 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-545136 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-545136\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"545137\" commentParentId=\"545136\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Harun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48372/avatar/15bf49d98279c433.jpg'/> </a>\n <div><a href=\"/profile/Harun\" title=\"Expert Harun\" class=\"rated-user user-blue\">Harun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2019 14:04\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-545137\" href=\"?#comment-545137\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-545136\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"545137\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48372\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-545137\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don’t even remember what I had for dinner last night and you’re here asking me about a code I wrote 6 years ago. That’s like a lot of months :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-545137 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-545137 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-545137\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"545138\" commentParentId=\"545137\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SevenDeadlySins\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/430874/avatar/b011182bef4f60f0.jpg'/> </a>\n <div><a href=\"/profile/SevenDeadlySins\" title=\"Pupil SevenDeadlySins\" class=\"rated-user user-green\">SevenDeadlySins</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2019 14:09\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-545138\" href=\"?#comment-545138\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-545137\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"545138\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"430874\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-545138\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>That can be answered with what language u used to code with... But anyway you have a point... and I got the ans after stalking your profile... Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-545138 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-545138 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-545138\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"174599\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dtalamas24\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60129/avatar/200478a7b9850d4b.jpg'/> </a>\n <div><a href=\"/profile/dtalamas24\" title=\"Candidate Master dtalamas24\" class=\"rated-user user-violet\">dtalamas24</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2014 09:33\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-174599\" href=\"?#comment-174599\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"174599\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"174599\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60129\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-174599\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Any online solutions for problem E ? Or different solutions to E?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-174599 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-174599 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-174599\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176403\" commentParentId=\"174599\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kllp\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/100053/avatar/44882b58f6756412.jpg'/> </a>\n <div><a href=\"/profile/kllp\" title=\"Master kllp\" class=\"rated-user user-orange\">kllp</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/02/2014 23:38\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176403\" href=\"?#comment-176403\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-174599\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"176403\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"100053\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176403\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My solution uses Heavy-light decomposition and segment trees. Complexity is O(N log^2 N). <a href=\"//codeforces.com/contest/342/submission/6999318\">http://codeforces.com/contest/342/submission/6999318</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176403 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176403 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176403\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"181789\" commentParentId=\"176403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Harun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/48372/avatar/15bf49d98279c433.jpg'/> </a>\n <div><a href=\"/profile/Harun\" title=\"Expert Harun\" class=\"rated-user user-blue\">Harun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/09/2014 17:53\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-181789\" href=\"?#comment-181789\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"181789\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"48372\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-181789\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could you explain your idea ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-181789 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-181789 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-181789\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"252934\" commentParentId=\"176403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/manmodeashish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/manmodeashish\" title=\"Specialist manmodeashish\" class=\"rated-user user-cyan\">manmodeashish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/28/2015 12:33\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-252934\" href=\"?#comment-252934\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"252934\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"226988\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-252934\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>very good. It was really helpful. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-252934 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-252934 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-252934\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"442050\" commentParentId=\"176403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cai_lw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/325977/avatar/202b61935928944.jpg'/> </a>\n <div><a href=\"/profile/cai_lw\" title=\"International Master cai_lw\" class=\"rated-user user-orange\">cai_lw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/02/2018 17:36\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-442050\" href=\"?#comment-442050\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"442050\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"325977\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-442050\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We can achieve O(NlogN) if we store each "heavy chains" in separate segment trees. For each operation, all queries and updates, except the beginning one, are on the whole chain, and only takes O(1). Therefore, each operation takes O(logN)*O(1)+O(1)*O(logN)=O(logN)</p><p><a href=\"//codeforces.com/contest/342/submission/39871066\">My solution</a> (it doesn't run faster in practice though)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-442050 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-442050 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-442050\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"213929\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mindbeats\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/56717/avatar/bcddf2e5600931f3.jpg'/> </a>\n <div><a href=\"/profile/mindbeats\" title=\"Expert mindbeats\" class=\"rated-user user-blue\">mindbeats</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2015 00:14\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-213929\" href=\"?#comment-213929\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"213929\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"56717\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-213929\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in problem E, the complexity is O(N * sqrtN * logN).... logN because of the LCA part it doesn't pass the time</p><p>how did you handle this !!?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-213929 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-213929 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-213929\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"937838\" commentParentId=\"213929\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Phantom_Performer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1746799/avatar/bc1dcacc56722125.jpg'/> </a>\n <div><a href=\"/profile/Phantom_Performer\" title=\"Master Phantom_Performer\" class=\"rated-user user-orange\">Phantom_Performer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/30/2022 17:45\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-937838\" href=\"?#comment-937838\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-213929\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"937838\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1746799\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-937838\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can precalculate the lca of nodes in Mlogn</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-937838 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-937838 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-937838\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"937911\" commentParentId=\"937838\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mindbeats\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/56717/avatar/bcddf2e5600931f3.jpg'/> </a>\n <div><a href=\"/profile/mindbeats\" title=\"Expert mindbeats\" class=\"rated-user user-blue\">mindbeats</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/31/2022 05:01\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-937911\" href=\"?#comment-937911\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-937838\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"937911\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"56717\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-937911\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>oh 7 years to get an answer...that was really too fast! :D </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-937911 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-937911 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-937911\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"316277\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2016 18:20\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-316277\" href=\"?#comment-316277\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"316277\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"316277\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-316277\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Deleted</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-316277 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-316277 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-316277\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"335462\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/....\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/....\" title=\"Expert ....\" class=\"rated-user user-blue\">....</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/04/2017 21:36\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-335462\" href=\"?#comment-335462\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"335462\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"335462\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"490997\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-335462\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem <a href=\"/contest/342/problem/E\" title=\"Codeforces Round 199 (Div. 2)\">342E - Xenia and Tree</a>, I came across a centroid decomposition solution <a href=\"/contest/342/submission/23224047\" title=\"Submission 23224047 by raiden_11\">23224047</a>. I have gone through the solution, but I am not able to convince myself about the correctness of the algorithm and the reason as to why query method is correct(or works). Please help!</p><p>PS: <a class=\"rated-user user-violet\" href=\"/profile/HolkinPV\" title=\"Candidate Master HolkinPV\">HolkinPV</a>, can you please help?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-335462 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-335462 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-335462\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"528302\" commentParentId=\"335462\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/VLADO\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/630234/avatar/e6872ed793f74338.jpg'/> </a>\n <div><a href=\"/profile/VLADO\" title=\"Expert VLADO\" class=\"rated-user user-blue\">VLADO</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/19/2019 15:37\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-528302\" href=\"?#comment-528302\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-335462\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"528302\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"630234\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-528302\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm a bit late but the solution is explained <a href=\"https://threads-iiith.quora.com/Centroid-Decomposition-of-a-Tree\">here</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-528302 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-528302 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-528302\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"370331\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/S.Jindal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/508955/avatar/43cfebadfb0dea2c.jpg'/> </a>\n <div><a href=\"/profile/S.Jindal\" title=\"Candidate Master S.Jindal\" class=\"rated-user user-violet\">S.Jindal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/29/2017 07:28\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-370331\" href=\"?#comment-370331\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"370331\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"508955\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-370331\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve Div1,C if we have to return the maximum distance to any red node instead of min distance...?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-370331 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-370331 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-370331\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371401\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nitesh_gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/454345/avatar/88dd212e02074fb0.jpg'/> </a>\n <div><a href=\"/profile/nitesh_gupta\" title=\"Master nitesh_gupta\" class=\"rated-user user-orange\">nitesh_gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/03/2017 11:52\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371401\" href=\"?#comment-371401\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"371401\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"371401\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"454345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371401\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"Distance between two nodes dist(u, v) can be got using preprocessing for lca." - Xenia and Tree</p><p>Can anyone explain me how to do it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371401 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371401 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371401\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371545\" commentParentId=\"371401\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MasT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/451310/avatar/10587ffa9ae01331.jpg'/> </a>\n <div><a href=\"/profile/MasT\" title=\"Expert MasT\" class=\"rated-user user-blue\">MasT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2017 07:00\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371545\" href=\"?#comment-371545\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371401\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"371545\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"371545\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"451310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371545\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Notice that <code>dist(u, v) = dist(root, u) + dist(root, v) - 2 * dist(root, l)</code>, where l is the LCA of u and v</p><p>1) Use a DFS to find the distance from node 1 (the root) to every other node. Let <code>rootDist[n]</code> by the distance from node 1 to node n. The DFS should also find the parent of each node, and the depth of each node from the root. Let <code>parent[n]</code> be the parent of node n and <code>depth[n]</code> be the depth of node n.</p><p>Example DFS code:</p> <pre><code>//Let MAX be the number of maximum nodes\nvector<int> adj[MAX];\nint rootDist[MAX], parent[MAX], depth[MAX];\n\n// cur = Current traversing node\n// prev = Node traversed before this one\nint dfs(int cur, int prev){\n parent[cur] = prev;\n\n for(int child : adj[cur]){\n if(child != prev){\n depth[child] = depth[cur] + 1;\n rootDist[child] = rootDist[cur] + 1;\n // Note: In the case of an unweighted tree,\n // depth[n] == rootDist[n]\n\n dfs(child, cur);\n\n }\n }\n}\n\ndfs(1, -1);\n</code></pre><p>2) Build a sparse table. <code>sparse[u][i]</code> stores the 2**i-th parent of u, or <code>-1</code> if that parent doesn't exist. Note that <code>sparse[u][0] = parent[n]</code>. The sparse table can be built by:</p> <pre><code>// N = number of nodes as given in input\n// LN = ceil(log2(Max number of nodes))\n// Using 1-indexing for nodes\nint sparse[MAX][LN];\nmemset(sparse, -1, sizeof sparse);\n\nfor(int u = 1; u <= N; u++)\n sparse[u][0] = parent[u];\n\nfor(int i = 1; i < LN; i++)\n for(int u = 1; u <= N; u++)\n //if the node has a 2**(i - 1)th parent\n if(sparse[u][i - 1] != -1)\n // the 2**i-th parent of u is equal to\n // the 2**(i - 1)th parent of 2**(i - 1)th parent of u\n sparse[u][i] = sparse [ sparse[u][i - 1] ] [i - 1];\n</code></pre><p>3) To query the lca of u and v, we do the following steps:</p> <ol> <li>If u has a smaller depth than v, swap them</li> <li>Find the ancestor of u with the same depth of v</li> <li>If u and v are the same node, return it</li> <li>Find the highest (least depth) ancestor of u and v (let's call them u' and v') such that u' is not v'</li> <li>Return the parent of u' (which is equal to the parent of v')</li> </ol><p>Here is the code for the query:</p> <pre><code>int lca(int u, int v){\n if(depth[u] < depth[v])\n swap(u, v);\n\n // We use sparse table so we jump 2**i parents each time\n // Taking only log time\n for(int i = LN - 1; i >= 0; i--)\n // If the 2**i-th parent of u isn't higher than v\n if(depth[ sparse[u][i] ] >= depth[v])\n // Go up 2**i parents\n u = sparse[u][i];\n\n // At this point, depth[u] == depth[v]\n // If they happen to be the same node, that is the LCA\n if(u == v)\n return u;\n\n for(int i = LN - 1; i >= 0; i--){\n // If their ancestors aren't the same\n if(sparse[u][i] != sparse[v][i]){\n // Go up to their ancestor\n u = sparse[u][i];\n v = sparse[v][i];\n }\n }\n\n // At this point, they're at the highest ancestor\n // such that they're not the same, so one parent above\n // must be their LCA\n\n // 2**0 = 1, return first parent of u\n return sparse[u][0];\n // this is also equal to sparse[v][0]\n}\n</code></pre><p>And finally, to put it all together, to query distance</p> <pre><code>int dist(int u, int v){\n int l = lca(u, v);\n return rootDist[u] + rootDist[v] - 2 * rootDist[l];\n}\n</code></pre><p>Building the LCA sparse table takes <code>O(n log n)</code> time while querying takes <code>O(log n)</code> time</p><p>(I wrote this from memory; please tell me if there are any mistakes or if any part is confusing)</p><p><a href=\"https://www.topcoder.com/community/data-science/data-science-tutorials/range-minimum-query-and-lowest-common-ancestor/\">Source/Additional reading</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371545 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371545 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371545\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371617\" commentParentId=\"371545\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nitesh_gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/454345/avatar/88dd212e02074fb0.jpg'/> </a>\n <div><a href=\"/profile/nitesh_gupta\" title=\"Master nitesh_gupta\" class=\"rated-user user-orange\">nitesh_gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2017 20:32\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371617\" href=\"?#comment-371617\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371545\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"371617\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"454345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371617\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for your help. You explained very well.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371617 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371617 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371617\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"425765\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sonupmandal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/356694/avatar/a3df14f7c5265075.jpg'/> </a>\n <div><a href=\"/profile/sonupmandal\" title=\"Pupil sonupmandal\" class=\"rated-user user-green\">sonupmandal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/18/2018 07:38\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-425765\" href=\"?#comment-425765\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"425765\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"356694\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-425765\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to do this - Calculate minimum distances from every node to the closest red node using bfs.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-425765 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-425765 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-425765\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"432106\" commentParentId=\"425765\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kayak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/700181/avatar/ec3f04c38ba70bde.jpg'/> </a>\n <div><a href=\"/profile/kayak\" title=\"Expert kayak\" class=\"rated-user user-blue\">kayak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2018 18:49\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-432106\" href=\"?#comment-432106\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-425765\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"432106\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"432106\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"700181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-432106\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Store all nodes which are currently red in a vector redlist. Create an queue bfslist for bfs, and create a array <code>dist[v] = Distance from v to the nearest red node, 0 if v is itself red</code> and initialize an empty queue. Now for all red vertices <span class=\"tex-span\"><i>v</i></span>, let <code>dist[v] = 0</code> and push all the neighbours <span class=\"tex-span\"><i>u</i></span> of the red vertices which are not red into this queue, and for all such <span class=\"tex-span\"><i>u</i></span>, let <code>dist[u] = 1, isdiscovered[u] = 1</code>. Now it's just regular bfs: while the queue is nonempty, pop the first element <code>w</code> from the queue, and add all the neighbours <code>y</code> of <code>w</code> not already discovered to the queue, and let <code>dist[y] = dist[w] +1, isdiscovered[y] = 1</code>. Here's a code implementing it:</p> <pre><code>void bfs(){\n std::queue<int> bfslist;\n int isdisc[N] = {0};\n for (int i = 0; i < red.size(); i +=1){\n int a = red[i];\n reddist[a] = 0;\n isdisc[i] = 1;\n for (int j = 0; j < adjlist[a].size(); j +=1){\n int b = adjlist[a][j];\n if ((isred[b] == 1) && (isdisc[b] == 0)){\n bfslist.push(b);\n reddist[b] = 1;\n isdisc[b] = 1;\n }\n }\n }\n while (!bfslist.empty()){\n int a = bfslist.front();\n bfslist.pop();\n for (int i = 0; i < adjlist[a].size(); i +=1){\n int b = adjlist[a][i];\n if ((isred[b] ==1) && (isdisc[b] == 0)){\n bfslist.push(b);\n reddist[b] = reddist[a]+1;\n isdisc[b] = 1;\n }\n }\n }\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-432106 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-432106 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-432106\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"446034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arjitkansal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/542324/avatar/cb05cf6d94faff9c.jpg'/> </a>\n <div><a href=\"/profile/arjitkansal\" title=\"Master arjitkansal\" class=\"rated-user user-orange\">arjitkansal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/18/2018 09:51\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-446034\" href=\"?#comment-446034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"446034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"542324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-446034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, can anyone please help me debug this code for Problem E. </p><p><a href=\"https://codeforces.com/contest/342/submission/39819558\">https://codeforces.com/contest/342/submission/39819558</a></p><p>It has been days and I've not been able to find the error.</p><p>I used 'Centroid Decomposition'.</p><p>Thanks in Advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-446034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-446034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-446034\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"566831\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ac_97\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1211001/avatar/6e08c927b196de27.jpg'/> </a>\n <div><a href=\"/profile/ac_97\" title=\"Specialist ac_97\" class=\"rated-user user-cyan\">ac_97</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/24/2019 00:32\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-566831\" href=\"?#comment-566831\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"566831\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1211001\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-566831\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem Div2 E, can someone share the code implementing the sqrt optimization trick. Are there any resources for this technique ? In what all cases can this technique be applied ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-566831 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-566831 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-566831\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"598414\" commentParentId=\"566831\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Skeef79\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631759/avatar/3033511aaec49179.jpg'/> </a>\n <div><a href=\"/profile/Skeef79\" title=\"Candidate Master Skeef79\" class=\"rated-user user-violet\">Skeef79</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/06/2020 13:06\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-598414\" href=\"?#comment-598414\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-566831\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"598414\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"631759\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-598414\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://pastebin.com/cCYBLvjs\">https://pastebin.com/cCYBLvjs</a></p><p><a href=\"https://codeforces.com/contest/342/submission/75643716\">https://codeforces.com/contest/342/submission/75643716</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-598414 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-598414 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-598414\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"584071\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mooncrater\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/656776/avatar/d19b34b1e226e4ad.jpg'/> </a>\n <div><a href=\"/profile/Mooncrater\" title=\"Specialist Mooncrater\" class=\"rated-user user-cyan\">Mooncrater</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/26/2020 20:31\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-584071\" href=\"?#comment-584071\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"584071\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"656776\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-584071\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div2 C, what comments?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-584071 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-584071 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-584071\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"913528\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mynameisminh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/mynameisminh\" title=\"Newbie mynameisminh\" class=\"rated-user user-gray\">mynameisminh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2022 19:24\">17 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-913528\" href=\"?#comment-913528\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"913528\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2253580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-913528\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can somebody help me with problems 342E. Here's my source code: <a href=\"https://codeforces.com/problemset/submission/342/157723527\">https://codeforces.com/problemset/submission/342/157723527</a></p><p>I still don't know why I got TLE. Thanks so much!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-913528 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-913528 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-913528\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"924618\" commentParentId=\"913528\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lite_27\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2584952/avatar/d7812158a0f2af9b.jpg'/> </a>\n <div><a href=\"/profile/lite_27\" title=\"Specialist lite_27\" class=\"rated-user user-cyan\">lite_27</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2022 23:07\">16 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-924618\" href=\"?#comment-924618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-913528\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"924618\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"924618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2584952\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-924618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-924618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-924618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-924618\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8871\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8871 = true;\r\nvar lastPreviewContent8871 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8871] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8871] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8855\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8855, _tta: Codeforces.tta(), topicRevisionId: 31374, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8855\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8855, _tta: Codeforces.tta(), topicRevisionId: 31374, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:21</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'81287486695d9d99',t:'MTY5NjcwNTk0MS43NDgwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1737,"cells":{"problem_id":{"kind":"string","value":"343A"},"contest":{"kind":"string","value":"343"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Rational Resistance"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Rational Resistance</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike is building a time machine in his spare time. To finish the work, he needs a resistor with a certain resistance value.</p><p>However, all Mike has is lots of identical resistors with unit resistance <span class=\"tex-span\"><i>R</i><sub class=\"lower-index\">0</sub> = 1</span>. Elements with other resistance can be constructed from these resistors. In this problem, we will consider the following as elements: </p><ol> <li> one resistor; </li><li> an element and <span class=\"tex-font-style-bf\">one</span> resistor plugged in sequence; </li><li> an element and <span class=\"tex-font-style-bf\">one</span> resistor plugged in parallel. </li></ol><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/fc5dca8df3a2578a728607daccf946b754d1cd00.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>With the consecutive connection the resistance of the new element equals <span class=\"tex-span\"><i>R</i> = <i>R</i><sub class=\"lower-index\"><i>e</i></sub> + <i>R</i><sub class=\"lower-index\">0</sub></span>. With the parallel connection the resistance of the new element equals <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/8e69f2f9d85e6584607971a68a207b22774fdf76.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>. In this case <span class=\"tex-span\"><i>R</i><sub class=\"lower-index\"><i>e</i></sub></span> equals the resistance of the element being connected.</p><p>Mike needs to assemble an element with a resistance equal to the fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>. Determine the smallest possible number of resistors he needs to make such an element.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The single input line contains two space-separated integers <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span> (<span class=\"tex-span\">1 ≤ <i>a</i>, <i>b</i> ≤ 10<sup class=\"upper-index\">18</sup></span>). It is guaranteed that the fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> is irreducible. It is guaranteed that a solution always exists.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single number — the answer to the problem.</p><p>Please do not use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in С++. It is recommended to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>199 200<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>200<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample, one resistor is enough.</p><p>In the second sample one can connect the resistors in parallel, take the resulting element and connect it to a third resistor consecutively. Then, we get an element with resistance <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5305da389756aab6423d918a08ced468f05604df.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>. We cannot make this element using two resistors.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"20791e189e107431441f21ef9bf18f5c\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"c35c56cdf057f72810b979434cacadcbf2ca863c\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='20791e189e107431441f21ef9bf18f5c'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F343%2Fproblem%2FA%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='20791e189e107431441f21ef9bf18f5c'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/343\">Codeforces Round 200 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='20791e189e107431441f21ef9bf18f5c'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/343/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Number theory: Euler function, GCD, divisibility, etc\">\r\n number theory\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1600\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='20791e189e107431441f21ef9bf18f5c'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3467\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='20791e189e107431441f21ef9bf18f5c'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3467\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8851\" title=\"Codeforces Round #200\" target=\"_blank\">Codeforces Round #200</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1852:1853\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8860\" title=\"Codeforces Round #200 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1848:1849\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/343\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/343/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/343/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/343/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/343/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/343/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/343/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/343/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_db76c4acb6f2983c1afa3f291ea8f74003d217c7\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Rational Resistance</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike is building a time machine in his spare time. To finish the work, he needs a resistor with a certain resistance value.</p><p>However, all Mike has is lots of identical resistors with unit resistance <span class=\"tex-span\"><i>R</i><sub class=\"lower-index\">0</sub> = 1</span>. Elements with other resistance can be constructed from these resistors. In this problem, we will consider the following as elements: </p><ol> <li> one resistor; </li><li> an element and <span class=\"tex-font-style-bf\">one</span> resistor plugged in sequence; </li><li> an element and <span class=\"tex-font-style-bf\">one</span> resistor plugged in parallel. </li></ol><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/fc5dca8df3a2578a728607daccf946b754d1cd00.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>With the consecutive connection the resistance of the new element equals <span class=\"tex-span\"><i>R</i> = <i>R</i><sub class=\"lower-index\"><i>e</i></sub> + <i>R</i><sub class=\"lower-index\">0</sub></span>. With the parallel connection the resistance of the new element equals <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/8e69f2f9d85e6584607971a68a207b22774fdf76.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. In this case <span class=\"tex-span\"><i>R</i><sub class=\"lower-index\"><i>e</i></sub></span> equals the resistance of the element being connected.</p><p>Mike needs to assemble an element with a resistance equal to the fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Determine the smallest possible number of resistors he needs to make such an element.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The single input line contains two space-separated integers <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span> (<span class=\"tex-span\">1 ≤ <i>a</i>, <i>b</i> ≤ 10<sup class=\"upper-index\">18</sup></span>). It is guaranteed that the fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> is irreducible. It is guaranteed that a solution always exists.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single number — the answer to the problem.</p><p>Please do not use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in С++. It is recommended to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>199 200<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>200<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample, one resistor is enough.</p><p>In the second sample one can connect the resistors in parallel, take the resulting element and connect it to a third resistor consecutively. Then, we get an element with resistance <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5305da389756aab6423d918a08ced468f05604df.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. We cannot make this element using two resistors.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:33</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bd6fbf1c169f',t:'MTY5NjY0NjAxMy41NjUwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Mathematics including integration, differential equations, etc\", \"Number theory: Euler function, GCD, divisibility, etc\"]"},"short_tags":{"kind":"string","value":"[\"math\", \"number theory\", \"*1600\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8860"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"21ba25574a0615e5dc71db6e32a512d8\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #200 Tutorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #200 Tutorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='21ba25574a0615e5dc71db6e32a512d8'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8860\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/gen\">gen</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gen\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gen\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gen\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gen\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gen\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gen\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gen\" style=\"text-decoration:none;color:black !important;\">gen's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8915\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8860\"> <p>Codeforces Round #200 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a>,\r\n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h4><a href=\"/contest/344/problem/A\" title=\"Codeforces Round 200 (Div. 2)\">344A - Magnets</a></h4><p>By the definition each block consists of a number of consequent and equally oriented dominoes. That means that in places where adjacent dominoes are not oriented equally, one block ends and another block starts. So, if there are <span class=\"tex-span\"><i>x</i></span> such places, the answer is equal to <span class=\"tex-span\"><i>x</i> + 1</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> The problem was created a day before the contest and filled in the last part of a physically flavoured DivII complect. :]</p><h4><a href=\"/contest/344/problem/B\" title=\"Codeforces Round 200 (Div. 2)\">344B - Simple Molecules</a></h4><p>First solution. First, the sum <span class=\"tex-span\"><i>a</i> + <i>b</i> + <i>c</i></span> should be even, since each bond adds 2 to the sum. Now let <span class=\"tex-span\"><i>x</i></span>, <span class=\"tex-span\"><i>y</i></span>, <span class=\"tex-span\"><i>z</i></span> be the number of bonds between 1st and 2nd, 2nd and 3rd, 3rd and 1st atoms, accordingly. So we have to solve the system <span class=\"tex-span\"><i>x</i> + <i>z</i> = <i>a</i></span>, <span class=\"tex-span\"><i>y</i> + <i>x</i> = <i>b</i></span>, <span class=\"tex-span\"><i>z</i> + <i>y</i> = <i>c</i></span>. Now observe that the solution to the system is the length of the tangents on the triangle with sides of length <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span> to its inscribed circle, and are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/2cee22ffa44dda3ce1b315e8cceef38c6288cf2c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1aed1c363b13d01e1b412b9cd3d5e34d19eb9c96.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/30fbfc651674588cadbee1fedd1e4b0d08d1ad4e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. If the problem asked only the possibility of building such a molecule, we could just check if there exists (possibly degenerate) triangle with sides <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span>.</p><p><img alt=\" \" src=\"/predownloaded/e3/d3/e3d3c930f4f93ca68c1e61630a2771472ecbd60a.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Second solution. Bruteforce all <span class=\"tex-span\"><i>x</i></span> values. For a fixed <span class=\"tex-span\"><i>x</i></span> values of <span class=\"tex-span\"><i>y</i></span> and <span class=\"tex-span\"><i>z</i></span> are defined uniquely: <span class=\"tex-span\"><i>y</i> = <i>b</i> - <i>x</i></span>, <span class=\"tex-span\"><i>z</i> = <i>a</i> - <i>x</i></span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(1) / <i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> Can you solve the problem for any vertex number <span class=\"tex-span\"><i>n</i></span>? When and how can such a graph be built?</p><h4><a href=\"/contest/343/problem/A\" title=\"Codeforces Round 200 (Div. 1)\">343A - Rational Resistance</a></h4><p>If a fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> can be obtained with <span class=\"tex-span\"><i>k</i></span> resistors, then it is simple to calculate that we can obtain fractions <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b6913fd8136f518e8a7898a9b759b74c4d483101.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/daf9572f0aa7677d7961c329e6277818df63bd9f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> with <span class=\"tex-span\"><i>k</i> + 1</span> resistors. So adding one resistor means performing one operation backwards in Euclidean algorithm. That means that the answer is equal to the number of steps in standard Euclidean algorithm.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e847ae811adbd761fa24db4ba7a6827e0806d670.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Бонус:</strong> At first we thought about the major problem (any two elements can be joined), but had a moment of eureka and got that the given problem unexpectedly naturally can be reduced to GCD. By the way, the result tree — <a href=\"https://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree\">http://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree</a>.</p><h4><a href=\"/contest/343/problem/B\" title=\"Codeforces Round 200 (Div. 1)\">343B - Alternating Current</a></h4><p>Let us solve the following problem first: we are given a string of symbols A and B. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>A</i></span>, then at the <span class=\"tex-span\"><i>i</i></span>-th step the upper wire (see figure) is being put over the lower wire. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>B</i></span>, the lower wire is being put over the upper wire at <span class=\"tex-span\"><i>i</i></span>-th step. Observe that if some two symbols <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are adjacent, we can untangle this place, throw the symbols out and obtain the string of length two symbols less. So the wires can be untangled iff the number of A's and B's in the string is the same. The given problem can be reduced to the described in a following fashion: in each odd position we change – to B and + to A. In each even position we change — to A and + to B. The reduction is correct, since on each even position the order of — and + are always swapped, and in each odd position their order is the same as in the beginning.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> If you are interested by this problem, you can learn about the braid theory <a href=\"https://en.wikipedia.org/wiki/Braid_theory\">http://en.wikipedia.org/wiki/Braid_theory</a> :] Fun fact: a harder version of this problem was planned already for Round #142, but the error in solution idea was found, and the problem was left to lay for almost a year.</p><h4><a href=\"/contest/343/problem/C\" title=\"Codeforces Round 200 (Div. 1)\">343C - Read Time</a></h4><p>Let's search the answer <span class=\"tex-span\"><i>t</i></span> with the binary search. Fix some value of <span class=\"tex-span\"><i>t</i></span>. Look at the first head from the left <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> that can read track <span class=\"tex-span\"><i>p</i>[0]</span>. If <span class=\"tex-span\"><i>p</i>[0] > <i>h</i>[<i>i</i>]</span>, then <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> goes to the right <span class=\"tex-span\"><i>t</i></span> seconds and reads all tracks on its way. Otherwise if <span class=\"tex-span\"><i>p</i>[0] ≤ <i>h</i>[<i>i</i>]</span>, then the head has two choices:</p> <ol> <li>go to the right <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> seconds, then <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> to the left and <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> again to the left;</li> <li>go to the left <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> seconds, then <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> to the right and <span class=\"tex-span\"><i>t</i> - 2·(<i>h</i>[<i>i</i>] - <i>p</i>[0])</span> again to the right.</li> </ol><p>Obviously, for <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> it is more advantageous to visit the track positioned as much as possible to the right. So we choose by <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7edc4f5554e1d173945160b7deaca92e61d7a755.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Then we move the pointer onto the first unread track, and repeat the algorithm for <span class=\"tex-span\"><i>h</i>[<i>i</i> + 1]</span>, and so on with each head.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/3342f24e1fd6ab939313f6d6278245c95d89544f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a>.</p><p><strong>Bonus:</strong> The problem is completely real, if the disk has only a single head, if we know, what tracks should be read; then the optimal algorithm chooses between the two choices described above. I and <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a> were listening this on a lecture, and created the given problem out of boredom ;]</p><h4><a href=\"/contest/343/problem/D\" title=\"Codeforces Round 200 (Div. 1)\">343D - Water Tree</a></h4><p>Let's learn how to color a whole subtree. For that enumerate all vertices in post-order DFS. Then each subtree covers a single continious vertex number segment. For each vertex we store the bounds of such segment for a subtree with a root in this vertex. Then to color a subtree means to color a segment in a segment tree.</p><p>Then create a segment tree that has a following property: if a vertex <span class=\"tex-span\"><i>v</i></span> was emptied, and is still empty, then this vertex is colored in the segment tree. In the beginning "empty" all the vertices. That is, color all the vertices in the segment tree. With this tree we can efficiently process the queries:</p> <ol> <li><p>Fill a vertex <span class=\"tex-span\"><i>v</i></span>. Clean the interval for the subtree of <span class=\"tex-span\"><i>v</i></span>. If before that some vertex of a subtree was empty, color the parent of <span class=\"tex-span\"><i>v</i></span>.</p></li> <li><p>Empty a vertex <span class=\"tex-span\"><i>v</i></span>. Color the vertex <span class=\"tex-span\"><i>v</i></span> in the segment tree.</p></li> <li><p>Reply whether a vertex <span class=\"tex-span\"><i>v</i></span> is filled. If in the segment tree at least one vertex is colored, then there is such a descendant of <span class=\"tex-span\"><i>v</i></span> that is empty now, so the vertex <span class=\"tex-span\"><i>v</i></span> is not filled.</p></li> </ol><p><a class=\"rated-user user-blue\" href=\"/profile/Shtrix\" title=\"Expert Shtrix\">Shtrix</a> noted that essentially the same solution can be implemented with only a single set.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fcb5cb34164112e0db4b3ef4b921f55df7ffb005.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> Some participants could see the similarities with a problem Ball Machine from BOI 2013, but the solutions to the both problems are quite different.</p><h4><a href=\"/contest/343/problem/E\" title=\"Codeforces Round 200 (Div. 1)\">343E - Pumping Stations</a></h4><p>In this problem we are asked to find such graph vertex permutation that maximizes the sum of the maximum flows sent between each two consequtive vertices in the permutation.</p><p>The problem can be solved with <a href=\"https://en.wikipedia.org/wiki/Gomory%E2%80%93Hu_tree\">Gomory-Hu</a> tree data structure. For a given weighted graph the tree has the following properties:</p> <ol> <li>The vertex set of the tree and the graph is the same.</li> <li>The maximum flow between vertices <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> in the tree is equal to the maximum flow in the graph.</li> </ol><p>Surprisingly, such a tree exists for any weighted graph, and can be built in <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. It appears that the answer to the problem is equal to the sum of the edge weights in this tree.</p><p>We prove this statement by induction on the number of the tree vertices. Pick the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> with the smallest weight in the tree. Consider that in an optimal permutation more than one path between two adjacent verteces in the permutation passes through this edge. Erase all these paths, then each of the <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> subtrees holds a set of disjoint remaining paths from the permutation. For each set, join all the paths in one chain, obtaining two chains. These chains we join by a path <span class=\"tex-span\"><i>s</i></span> that goes trough the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>. Thus we have built a permutation that is not worse than the considered one. For a path <span class=\"tex-span\"><i>s</i></span> the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> is the smallest, so the flow along this path is equal to the weight of this edge. It follows from the induction that in subtrees <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> the answer is equal to the sum of edges. By adding the weight of edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>, we get the desired result.</p><p>From the last paragraph it is clear how to build such a permutation: take the smallest edge, obtain two chains from the vertex subtrees recursively, and add them together to form a one chain. Since there are not many vertices, we can do this part in <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-orange\" href=\"/profile/Gerald\" title=\"Master Gerald\">Gerald</a>.</p><p><strong>Bonus:</strong> Shortly before the contest we decided to make the constraints more loyal, so some solution that find Gomory-Hu tree by finding flow <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> times also passed. We hope that nobody is particularly saddened by this fact. (;</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/343\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/344\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-8915\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"8860\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=200\" class=\"tag notice\" style=\"text-decoration: none;\">200</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+64</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8860#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8860#comments\">\n 53\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8931\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (43)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145823\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bipinb1994\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/91315/avatar/b4e2d8ac5b2569a3.jpg'/> </a>\n <div><a href=\"/profile/bipinb1994\" title=\"Expert bipinb1994\" class=\"rated-user user-blue\">bipinb1994</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 07:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145823\" href=\"?#comment-145823\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145823\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-15\"\r\n data-commentUserId=\"91315\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145823\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hai this was my first round in Codeforces. But my code was not accepted and it says that it was wrong with the 3rd test case. What i did was put a loop from 0 to n-1 and i checked ch[i][!=ch[i+1][0] then count++; else continue where 'ch' is the character array(2-D) whose size was Nx3 ...Is this algorithm completely wrong. As i said this was the first round here i did not understand what is wrong with this. If possible please do tell me what is wrong with this algorithm..:(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145823 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145823 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145823\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145863\" commentParentId=\"145823\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 14:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145863\" href=\"?#comment-145863\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145823\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145863\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145863\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please look at link <a href=\"//codeforces.com/contest/344/submission/4461494\">http://codeforces.com/contest/344/submission/4461494</a>. </p><p>The log says</p><p>Time: 0 ms, memory: 0 KB Verdict: WRONG_ANSWER Input 1 10 Output 0 Answer 1 Checker comment wrong answer 1st numbers differ — expected: '1', found: '0'</p><p>I believe this should be self explanatory. </p><p>Also it would help playing around with the system before trying to enter a rated match.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145863 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145863 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145863\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146026\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ka16\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ka16\" title=\"Pupil ka16\" class=\"rated-user user-green\">ka16</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 06:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146026\" href=\"?#comment-146026\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146026\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"12131\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146026\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody please clarify the two choices of head(s) in the solution of 343C-Read Time problem above? I couldn't understand it completely. Thank in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146026 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146026 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146026\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146037\" commentParentId=\"146026\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hriss95\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27396/avatar/d6cec8eac7bdbde3.jpg'/> </a>\n <div><a href=\"/profile/hriss95\" title=\"Expert hriss95\" class=\"rated-user user-blue\">hriss95</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 13:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146037\" href=\"?#comment-146037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146026\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146037\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"27396\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have to choose one of the two types moving: first to the right or first to the left. You have to use the one which covers more points to the right. Note that both types of moving cover the left point and that's why you have to take as much as points as you can to the right.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146037\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sorin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/sorin\" title=\"Expert sorin\" class=\"rated-user user-blue\">sorin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 12:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146034\" href=\"?#comment-146034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"124904\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody give me a hint for the bonus at Div2 — B? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146034\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146064\" commentParentId=\"146034\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 21:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146064\" href=\"?#comment-146064\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146034\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146064\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146064\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Think greedy ;]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146064 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146064 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146064\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"152157\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ghooo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2010/avatar/659a8aca8b12506a.jpg'/> </a>\n <div><a href=\"/profile/ghooo\" title=\"Master ghooo\" class=\"rated-user user-orange\">ghooo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/26/2013 08:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-152157\" href=\"?#comment-152157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"152157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2010\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-152157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>will the connections between the atoms be circular? like 1 <-> 2 <-> 3 <-> 4 <-> 5 ... n <-> 1 (again) ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-152157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-152157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-152157\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"521750\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/n0tred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1177564/avatar/a46e0281e87dd6c9.jpg'/> </a>\n <div><a href=\"/profile/n0tred\" title=\"Candidate Master n0tred\" class=\"rated-user user-violet\">n0tred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/25/2019 14:29\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-521750\" href=\"?#comment-521750\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"521750\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1177564\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-521750\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you give a better hint? (Maybe through a spoiler, I suppose)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-521750 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-521750 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-521750\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"523308\" commentParentId=\"521750\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/29/2019 09:36\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-523308\" href=\"?#comment-523308\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-521750\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"523308\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-523308\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the algorithm that continuously connects the vertex with the smallest degree with the vertex with the largest degree works (here by degree I mean the unconnected edges), and builds a connected graph. I think this can be proved by induction.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-523308 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-523308 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-523308\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146129\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 11:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146129\" href=\"?#comment-146129\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146129\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146129\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think there is an issue with Problem 343A — Rational Resistance. Here according to the editorial the answer to the ratio 6/5 would be 6(I have verified this with an accepted solution). But this ratio can be achieved with a resistance of 2 and 3 in parallel, which makes the number of resistors required equal to 5 which would imply the editorial and the system tests to be wrong.</p><p>Am I missing something here?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146129 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146129 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146129\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146259\" commentParentId=\"146129\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146259\" href=\"?#comment-146259\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146129\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146259\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146259\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think it's because the definition of <strong>one element</strong> only let you add <strong>one</strong> new unit resistor to another element</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146259 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146259 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146259\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146256\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146256\" href=\"?#comment-146256\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146256\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146256\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for the nice problems!</p><p>I just have a little question on 343C — Read Time. I use the same algorithm and get AC, but my algorithm is running at O(n log^2 n)... as for the step: "Then we move the pointer onto the first unread track" I use another binary search...</p><p>how can I implement the same algorithm with O(n log n) as said in editorial? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146256 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146256 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146256\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146269\" commentParentId=\"146256\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146269\" href=\"?#comment-146269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146256\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146269\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We hold two pointers: the first points at the first unread track from the left, and the second points at the first unused head so far. So we take this head and read with its help the maximum number of yet unread tracks (note that they are consequent and begin at the first pointer) according to the best of the two choices described in tutorial. Then we move the first pointer to the first yet unread track, and increment the second by one. Thus each pointer moves <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> times in this iteration of the binary search. Take also in consideration that some heads can be not used at all.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154161\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/s2k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146708/avatar/ec43946f377e5c64.jpg'/> </a>\n <div><a href=\"/profile/s2k\" title=\"Newbie s2k\" class=\"rated-user user-gray\">s2k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154161\" href=\"?#comment-154161\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154161\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146708\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154161\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi. I was just trying to solve problem A of division 2, but was unsuccessful after hours of effort. I eventually lost patience and decided to see the codes of others. I did understand what was going in the code, but couldn't figure out why this method was chosen in the first place. Can someone please help me understand the solution?</p><p>P.S. I'm a newbie with almost no prior knowledge about number theory. :$</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154161 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154161 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154161\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154163\" commentParentId=\"154161\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154163\" href=\"?#comment-154163\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-154161\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154163\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154163\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The number of islands is always one more than the number of splits between two neighboring dominoes. One can easily convince himself by looking at an image in the description.</p><p>There are 4 possibilities of neighboring dominoes:</p> <ul> <li>01 and 01: these attract, so they don't form a split and we don't care about them</li> <li>10 and 10: these attract, so they don't form a split and we don't care about them</li> <li>01 and 10: these don't attract, so they form a split</li> <li>10 and 01: these don't attract, so they form a split</li> </ul><p>So, we can deduce that we're only interested in neighboring dominoes that are different. This means we can just count the number of indexes i (1 <= i < N) such that s[i] != s[i+1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154163 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154163 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154163\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176652\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/S.Ged\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67184/avatar/a38f51555a40b56a.jpg'/> </a>\n <div><a href=\"/profile/S.Ged\" title=\"Candidate Master S.Ged\" class=\"rated-user user-violet\">S.Ged</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 04:10\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176652\" href=\"?#comment-176652\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"176652\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"176652\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"67184\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176652\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm confused by the first sentence of 343A — Rational Resistance tutorial</p><p>How can we obtain a/(a+b) with k+1 resistors if obatined a/b wiht k resistors ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176652 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176652 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176652\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176656\" commentParentId=\"176652\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/afrizal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/103639/avatar/206f6cf479b00060.jpg'/> </a>\n <div><a href=\"/profile/afrizal\" title=\"Expert afrizal\" class=\"rated-user user-blue\">afrizal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 07:05\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176656\" href=\"?#comment-176656\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176652\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"176656\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"103639\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176656\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Remember a/a is 1. If we have a/b resistance, put one more resistor parallel will give <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c1a16b55f7f10840909e0e5863ae3ce22e36c85b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176656 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176656 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176656\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"189636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/namikaze\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/227989/avatar/51e67e9e139a65f2.jpg'/> </a>\n <div><a href=\"/profile/namikaze\" title=\"Unrated, namikaze\" class=\"rated-user user-black\">namikaze</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/28/2014 15:45\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-189636\" href=\"?#comment-189636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"189636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"227989\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-189636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><code>adding one resistor means performing one operation backwards in Euclidean algorithm</code></p><p>Can someone explain this ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-189636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-189636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-189636\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"277029\" commentParentId=\"189636\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TomBombadil\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/106415/avatar/ed9d8ef375273241.jpg'/> </a>\n <div><a href=\"/profile/TomBombadil\" title=\"Specialist TomBombadil\" class=\"rated-user user-cyan\">TomBombadil</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2016 17:50\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-277029\" href=\"?#comment-277029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-189636\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"277029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"106415\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-277029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-orange\" href=\"/profile/gen\" title=\"Master gen\">gen</a> ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-277029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-277029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-277029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"351231\" commentParentId=\"277029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/R.A.X\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/122476/avatar/686763c746ac6e7b.jpg'/> </a>\n <div><a href=\"/profile/R.A.X\" title=\"Specialist R.A.X\" class=\"rated-user user-cyan\">R.A.X</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/27/2017 15:37\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-351231\" href=\"?#comment-351231\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-277029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"351231\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"351231\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"122476\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-351231\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Suppose you have resistance of(17/3), it could be formed by adding 1 + (14/3). If you have resistance of (3/17), it could be obtained by combining resistance of 1 and 3/14 in parallel.</p><p>In terms of variable, a/b could be obtained by 1 + resistors required to create ( a-b)/b resistance, assuming a>b. and a/b if b>a, could be obtained by 1 + resistors required to create ( a/(b-a) ).</p><p>Assuming a>b so resistorRequired(a,b) = 1 + resistorRequired(a-b,b).</p> <pre>resistorReqiored(a-b,b) = 1 + resistorRequired(a-2b,b)</pre><p>............</p> <pre>resistorRequired(a-(q-1)*b ,b) = 1 + resistorRequired(a-q*b,b)</pre><p>let say r = a-q*b == a%b now at this point, one resistance needs to be connected in parallel to the b/r resistance.</p><p>so again problem becomes calculating the requiredResistance(b,r) similar to above problem,</p><p>which is similar to the gcd problem.</p><p>Hope that helps.</p><p>Why it's like gcd(a,b) = gcd(a-b,b) =gcd(a-2b,b) .... </p><p>In case of gcd(a,b) = gcd(a-b,b)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-351231 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-351231 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-351231\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"393063\" commentParentId=\"351231\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ShafinKhadem\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/508696/avatar/1b5c8ae9cf51dc77.jpg'/> </a>\n <div><a href=\"/profile/ShafinKhadem\" title=\"Master ShafinKhadem\" class=\"rated-user user-orange\">ShafinKhadem</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/01/2017 09:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-393063\" href=\"?#comment-393063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-351231\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"393063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"508696\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-393063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for the nice explanation. Now the use of euclidian algorithm to solve this problem makes sense to me.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-393063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-393063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-393063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"220282\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CloverAsta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207753/avatar/45b71a38344fa830.jpg'/> </a>\n <div><a href=\"/profile/CloverAsta\" title=\"Expert CloverAsta\" class=\"rated-user user-blue\">CloverAsta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/01/2015 14:33\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-220282\" href=\"?#comment-220282\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"220282\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207753\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-220282\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain to me the solution for Problem C div2 I understand the transition from <code>k</code> to <code>k + 1</code> but the part about Euclidean algorithm is beyond me</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-220282 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-220282 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-220282\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"232136\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anajin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221428/avatar/b8f5979933e2ce3d.jpg'/> </a>\n <div><a href=\"/profile/anajin\" title=\"Expert anajin\" class=\"rated-user user-blue\">anajin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/03/2015 14:15\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-232136\" href=\"?#comment-232136\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"232136\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-232136\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>water tree can be solved by heavy-light decomposition...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-232136 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-232136 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-232136\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"454886\" commentParentId=\"232136\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cai_lw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/325977/avatar/202b61935928944.jpg'/> </a>\n <div><a href=\"/profile/cai_lw\" title=\"International Master cai_lw\" class=\"rated-user user-orange\">cai_lw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/30/2018 20:04\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-454886\" href=\"?#comment-454886\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-232136\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"454886\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"454886\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"325977\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-454886\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, this is almost the most standard problem for HLD. But their solution is cleverer and has lower time complexity. HLD is a little bit overkill for such simple operations.</p><p>Nevertheless, HLD can pass the test. My HLD solution passed in 900ms.</p><p>Also HLD was a relatively unknown algorithm to the CP community 5 years ago.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-454886 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-454886 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-454886\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"634570\" commentParentId=\"454886\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Suri429\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/776807/avatar/90399ec92a81320a.jpg'/> </a>\n <div><a href=\"/profile/Suri429\" title=\"Master Suri429\" class=\"rated-user user-orange\">Suri429</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2020 08:55\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-634570\" href=\"?#comment-634570\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-454886\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"634570\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"776807\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-634570\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain how to approach this with HLD? I am new to HLD, and not able to get any clue here. </p><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-634570 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-634570 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-634570\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"312598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/29/2016 12:31\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-312598\" href=\"?#comment-312598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"312598\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"312598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-312598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder why I did wrong in the implementation of lazy propagation for Div1D, could anyone kindly lend some help? </p><p><a href=\"//codeforces.com/contest/343/submission/20226349\">http://codeforces.com/contest/343/submission/20226349</a></p><p>Thanks in advance. =)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-312598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-312598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-312598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"357445\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anshulgarg19\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/anshulgarg19\" title=\"Pupil anshulgarg19\" class=\"rated-user user-green\">anshulgarg19</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/02/2017 20:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-357445\" href=\"?#comment-357445\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"357445\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"244328\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-357445\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Accepted solution for the problem 343A Rational Resistance would give 6 as the output for input a = 10 and b = 7 i.e.10/7. But, if we have 5 ohm and 2 ohm resistors in parallel, then we have the same resistance value 10/7. So minimum value should be 2 resistors for this case. Kindly explain if i am wrong in understanding the problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-357445 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-357445 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-357445\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360009\" commentParentId=\"357445\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/snehil10\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/351506/avatar/522f61633a219a3b.jpg'/> </a>\n <div><a href=\"/profile/snehil10\" title=\"Expert snehil10\" class=\"rated-user user-blue\">snehil10</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/14/2017 10:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360009\" href=\"?#comment-360009\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-357445\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"360009\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"351506\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360009\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have only 1-ohm resistors in the beginning. Thus it requires 5 1-ohm resistors to make a 5-ohm resistor, and 2 1-ohm resistors to make a 2-ohm resistor. So according to you answer is 7 and not 2.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360009 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360009 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360009\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371475\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rush_123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/rush_123\" title=\"Expert rush_123\" class=\"rated-user user-blue\">rush_123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/03/2017 17:42\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371475\" href=\"?#comment-371475\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"371475\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"439840\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371475\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 343D — Water Tree query 1 and 2 can be solved using a dfs to find in time and out time for every node and then using segment tree But what about 3rd query how to solve it?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371475 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371475 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371475\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"422269\" commentParentId=\"371475\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stringray\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/575608/avatar/2902babcf56868a2.jpg'/> </a>\n <div><a href=\"/profile/stringray\" title=\"Expert stringray\" class=\"rated-user user-blue\">stringray</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/28/2018 16:13\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-422269\" href=\"?#comment-422269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371475\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"422269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"575608\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-422269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yeah same question .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-422269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-422269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-422269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"437012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ragnarok_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ragnarok_\" title=\"Newbie ragnarok_\" class=\"rated-user user-gray\">ragnarok_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2018 08:59\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-437012\" href=\"?#comment-437012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"437012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"673189\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-437012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Q.343A can anybody explain me why min resistor for 199/200 is 200.....it can be also constructed using 101 resistors(1/2+1/4+1/5+1/40+1/50)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-437012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-437012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-437012\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"573631\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SLIMSHADYNICK\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/598862/avatar/7629f1b29f0fe807.jpg'/> </a>\n <div><a href=\"/profile/SLIMSHADYNICK\" title=\"Candidate Master SLIMSHADYNICK\" class=\"rated-user user-violet\">SLIMSHADYNICK</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2020 21:03\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-573631\" href=\"?#comment-573631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"573631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"598862\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-573631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>correct!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-573631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-573631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-573631\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587715\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pied-piper\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/754580/avatar/a6fb81d49bb96665.jpg'/> </a>\n <div><a href=\"/profile/pied-piper\" title=\"Expert pied-piper\" class=\"rated-user user-blue\">pied-piper</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/11/2020 16:14\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587715\" href=\"?#comment-587715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"587715\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"587715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"754580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It is because they are separate elements and hence they cannot be added together. Only an element and a 1 unit resistance can be added in series(or parallel)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587715\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"791297\" commentParentId=\"587715\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/15/2021 17:25\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-791297\" href=\"?#comment-791297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587715\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"791297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-791297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-791297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-791297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-791297\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"598229\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayank_ag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/644568/avatar/c1136e364e721d18.jpg'/> </a>\n <div><a href=\"/profile/mayank_ag\" title=\"Master mayank_ag\" class=\"rated-user user-orange\">mayank_ag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/05/2020 20:53\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-598229\" href=\"?#comment-598229\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"598229\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"644568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-598229\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>An alternate approach for solving D: Use of lazy segment tree over HLD & Euler path. For every filling, fill Euler path with current query number, and for emptying, fill HLD path from the root with query number. For queries, check which of the seg tree has high query number.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-598229 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-598229 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-598229\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"600816\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Asterix_11\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Asterix_11\" title=\"Pupil Asterix_11\" class=\"rated-user user-green\">Asterix_11</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/11/2020 00:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-600816\" href=\"?#comment-600816\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"600816\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1472760\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-600816\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem 344A</p> <pre><code>#include <iostream>\nusing namespace std;\nint main()\n{\n int a, i, b[100], ans;\n scanf("%d", &a);\n for(i = 0; i < a; ++i){\n scanf("%d", &b[i]);\n }\n ans = 1;\n for(i = 0; i < (a-1); ++i){\n if(b[i] != b[i + 1]){\n ++ans;}\n }\n printf("%d", ans);\n return 0;\n}\n</code></pre><p>This is my code, but I don't know how to improve it, so that the time limit won't be a problem anymore. Any help?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-600816 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-600816 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-600816\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752098\" commentParentId=\"600816\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 09:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752098\" href=\"?#comment-752098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-600816\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can make two variable for prev and current value and if they are not equal you can increment it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752098\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752075\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:25\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752075\" href=\"?#comment-752075\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752075\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752075\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Problem C, if more than one of the elements can be in parallel than for ratio 199 and 200 the answer given is 200. But we may solve this in 74. like 1/2+1/4+1/8+1/10+1/50.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752075 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752075 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752075\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752089\" commentParentId=\"752075\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752089\" href=\"?#comment-752089\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-752075\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752089\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752089\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Okay it would be like either + denominator to the numerator or + numerator to the denominator.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752089 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752089 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752089\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"946539\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mohsina_Shaikh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1396580/avatar/6f21616a2d8d578.jpg'/> </a>\n <div><a href=\"/profile/Mohsina_Shaikh\" title=\"Newbie Mohsina_Shaikh\" class=\"rated-user user-gray\">Mohsina_Shaikh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/24/2022 06:47\">13 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-946539\" href=\"?#comment-946539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"946539\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"946539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1396580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-946539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a> or <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a> or can anyone please explain <code>Alternating Current</code> Solution.Tried so hard but not able to understand it. A</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-946539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-946539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-946539\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"959164\" commentParentId=\"946539\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rishijoshi483\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2453886/avatar/1ecf48b346fe39d0.jpg'/> </a>\n <div><a href=\"/profile/rishijoshi483\" title=\"Expert rishijoshi483\" class=\"rated-user user-blue\">rishijoshi483</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/03/2022 09:44\">12 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-959164\" href=\"?#comment-959164\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-946539\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"959164\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2453886\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-959164\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try it using stack</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-959164 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-959164 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-959164\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"966651\" commentParentId=\"959164\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Yohajji\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2854745/avatar/b31d6e4c63852741.jpg'/> </a>\n <div><a href=\"/profile/Yohajji\" title=\"Newbie Yohajji\" class=\"rated-user user-gray\">Yohajji</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2022 13:35\">11 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-966651\" href=\"?#comment-966651\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-959164\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"966651\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2854745\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-966651\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>using the stack was a brilliant aproach, thank you </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-966651 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-966651 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-966651\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1039007\" commentParentId=\"966651\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AbdelrahmanMahallawy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3189297/avatar/6b2a1658ad37caa0.jpg'/> </a>\n <div><a href=\"/profile/AbdelrahmanMahallawy\" title=\"Newbie AbdelrahmanMahallawy\" class=\"rated-user user-gray\">AbdelrahmanMahallawy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/20/2023 03:36\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1039007\" href=\"?#comment-1039007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-966651\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1039007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3189297\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1039007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>anytime </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1039007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1039007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1039007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8931\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8931 = true;\r\nvar lastPreviewContent8931 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8931] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8931] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:23</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128748fcb8816ab',t:'MTY5NjcwNTk0My4yOTkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1738,"cells":{"problem_id":{"kind":"string","value":"343B"},"contest":{"kind":"string","value":"343"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Alternating Current"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Alternating Current</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike has just finished constructing a new device to search for extraterrestrial intelligence! He was in such a hurry to launch it for the first time that he plugged in the power wires without giving it a proper glance and started experimenting right away. After a while Mike observed that the wires ended up entangled and now have to be untangled again.</p><p>The device is powered by two wires \"plus\" and \"minus\". The wires run along the floor from the wall (on the left) to the device (on the right). Both the wall and the device have two contacts in them on the same level, into which the wires are plugged in some order. The wires are considered entangled if there are one or more places where one wire runs above the other one. For example, the picture below has four such places (top view):</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/d9893064977f0a3ba06c4b18908f20c7ef488731.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>Mike knows the sequence in which the wires run above each other. Mike also noticed that on the left side, the \"plus\" wire is always plugged into the top contact (as seen on the picture). He would like to untangle the wires without unplugging them and <span class=\"tex-font-style-bf\">without moving</span> the device. Determine if it is possible to do that. A wire can be freely moved and stretched on the floor, but cannot be cut.</p><p>To understand the problem better please read the notes to the test samples.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The single line of the input contains a sequence of characters \"<span class=\"tex-font-style-tt\">+</span>\" and \"<span class=\"tex-font-style-tt\">-</span>\" of length <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100000</span>). The <span class=\"tex-span\"><i>i</i></span>-th (<span class=\"tex-span\">1 ≤ <i>i</i> ≤ <i>n</i></span>) position of the sequence contains the character \"<span class=\"tex-font-style-tt\">+</span>\", if on the <span class=\"tex-span\"><i>i</i></span>-th step from the wall the \"plus\" wire runs above the \"minus\" wire, and the character \"<span class=\"tex-font-style-tt\">-</span>\" otherwise.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print either \"<span class=\"tex-font-style-tt\">Yes</span>\" (without the quotes) if the wires can be untangled or \"<span class=\"tex-font-style-tt\">No</span>\" (without the quotes) if the wires cannot be untangled.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>-++-<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Yes<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>+-<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>No<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>++<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Yes<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>-<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>No<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The first testcase corresponds to the picture in the statement. To untangle the wires, one can first move the \"plus\" wire lower, thus eliminating the two crosses in the middle, and then draw it under the \"minus\" wire, eliminating also the remaining two crosses.</p><p>In the second testcase the \"plus\" wire makes one full revolution around the \"minus\" wire. Thus the wires cannot be untangled: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/ab7cf5aedea609efdfcd91bf5ece433ff50d80fe.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>In the third testcase the \"plus\" wire simply runs above the \"minus\" wire twice in sequence. The wires can be untangled by lifting \"plus\" and moving it higher: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/c3d652f33419ce743e0f2e4e951b77f90915151b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>In the fourth testcase the \"minus\" wire runs above the \"plus\" wire once. The wires cannot be untangled without moving the device itself: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/ca61897e6664278c14115d010a07b6023c28e833.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"fd0d795addbba1fd1df99ab50ee29f92\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"c35c56cdf057f72810b979434cacadcbf2ca863c\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='fd0d795addbba1fd1df99ab50ee29f92'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F343%2Fproblem%2FB%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='fd0d795addbba1fd1df99ab50ee29f92'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/343\">Codeforces Round 200 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='fd0d795addbba1fd1df99ab50ee29f92'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/343/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Heaps, binary search trees, segment trees, hash tables, etc\">\r\n data structures\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1600\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='fd0d795addbba1fd1df99ab50ee29f92'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3468\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='fd0d795addbba1fd1df99ab50ee29f92'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3468\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8851\" title=\"Codeforces Round #200\" target=\"_blank\">Codeforces Round #200</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1852:1853\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8860\" title=\"Codeforces Round #200 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1848:1849\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/343\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/343/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/343/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/343/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/343/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/343/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/343/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/343/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_bc1f8f7b631582ae1ab3699579ec6f42d3dfb746\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Alternating Current</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike has just finished constructing a new device to search for extraterrestrial intelligence! He was in such a hurry to launch it for the first time that he plugged in the power wires without giving it a proper glance and started experimenting right away. After a while Mike observed that the wires ended up entangled and now have to be untangled again.</p><p>The device is powered by two wires "plus" and "minus". The wires run along the floor from the wall (on the left) to the device (on the right). Both the wall and the device have two contacts in them on the same level, into which the wires are plugged in some order. The wires are considered entangled if there are one or more places where one wire runs above the other one. For example, the picture below has four such places (top view):</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/d9893064977f0a3ba06c4b18908f20c7ef488731.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>Mike knows the sequence in which the wires run above each other. Mike also noticed that on the left side, the "plus" wire is always plugged into the top contact (as seen on the picture). He would like to untangle the wires without unplugging them and <span class=\"tex-font-style-bf\">without moving</span> the device. Determine if it is possible to do that. A wire can be freely moved and stretched on the floor, but cannot be cut.</p><p>To understand the problem better please read the notes to the test samples.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The single line of the input contains a sequence of characters "<span class=\"tex-font-style-tt\">+</span>" and "<span class=\"tex-font-style-tt\">-</span>" of length <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100000</span>). The <span class=\"tex-span\"><i>i</i></span>-th (<span class=\"tex-span\">1 ≤ <i>i</i> ≤ <i>n</i></span>) position of the sequence contains the character "<span class=\"tex-font-style-tt\">+</span>", if on the <span class=\"tex-span\"><i>i</i></span>-th step from the wall the "plus" wire runs above the "minus" wire, and the character "<span class=\"tex-font-style-tt\">-</span>" otherwise.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print either "<span class=\"tex-font-style-tt\">Yes</span>" (without the quotes) if the wires can be untangled or "<span class=\"tex-font-style-tt\">No</span>" (without the quotes) if the wires cannot be untangled.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>-++-<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Yes<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>+-<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>No<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>++<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Yes<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>-<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>No<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The first testcase corresponds to the picture in the statement. To untangle the wires, one can first move the "plus" wire lower, thus eliminating the two crosses in the middle, and then draw it under the "minus" wire, eliminating also the remaining two crosses.</p><p>In the second testcase the "plus" wire makes one full revolution around the "minus" wire. Thus the wires cannot be untangled: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/ab7cf5aedea609efdfcd91bf5ece433ff50d80fe.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>In the third testcase the "plus" wire simply runs above the "minus" wire twice in sequence. The wires can be untangled by lifting "plus" and moving it higher: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/c3d652f33419ce743e0f2e4e951b77f90915151b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>In the fourth testcase the "minus" wire runs above the "plus" wire once. The wires cannot be untangled without moving the device itself: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/ca61897e6664278c14115d010a07b6023c28e833.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:34</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bd7879523a89',t:'MTY5NjY0NjAxNC44NjkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Heaps, binary search trees, segment trees, hash tables, etc\", \"Greedy algorithms\", \"Implementation problems, programming technics, simulation\"]"},"short_tags":{"kind":"string","value":"[\"data structures\", \"greedy\", \"implementation\", \"*1600\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8860"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"21ba25574a0615e5dc71db6e32a512d8\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #200 Tutorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #200 Tutorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='21ba25574a0615e5dc71db6e32a512d8'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8860\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/gen\">gen</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gen\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gen\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gen\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gen\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gen\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gen\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gen\" style=\"text-decoration:none;color:black !important;\">gen's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8915\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8860\"> <p>Codeforces Round #200 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a>,\r\n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h4><a href=\"/contest/344/problem/A\" title=\"Codeforces Round 200 (Div. 2)\">344A - Magnets</a></h4><p>By the definition each block consists of a number of consequent and equally oriented dominoes. That means that in places where adjacent dominoes are not oriented equally, one block ends and another block starts. So, if there are <span class=\"tex-span\"><i>x</i></span> such places, the answer is equal to <span class=\"tex-span\"><i>x</i> + 1</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> The problem was created a day before the contest and filled in the last part of a physically flavoured DivII complect. :]</p><h4><a href=\"/contest/344/problem/B\" title=\"Codeforces Round 200 (Div. 2)\">344B - Simple Molecules</a></h4><p>First solution. First, the sum <span class=\"tex-span\"><i>a</i> + <i>b</i> + <i>c</i></span> should be even, since each bond adds 2 to the sum. Now let <span class=\"tex-span\"><i>x</i></span>, <span class=\"tex-span\"><i>y</i></span>, <span class=\"tex-span\"><i>z</i></span> be the number of bonds between 1st and 2nd, 2nd and 3rd, 3rd and 1st atoms, accordingly. So we have to solve the system <span class=\"tex-span\"><i>x</i> + <i>z</i> = <i>a</i></span>, <span class=\"tex-span\"><i>y</i> + <i>x</i> = <i>b</i></span>, <span class=\"tex-span\"><i>z</i> + <i>y</i> = <i>c</i></span>. Now observe that the solution to the system is the length of the tangents on the triangle with sides of length <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span> to its inscribed circle, and are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/2cee22ffa44dda3ce1b315e8cceef38c6288cf2c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1aed1c363b13d01e1b412b9cd3d5e34d19eb9c96.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/30fbfc651674588cadbee1fedd1e4b0d08d1ad4e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. If the problem asked only the possibility of building such a molecule, we could just check if there exists (possibly degenerate) triangle with sides <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span>.</p><p><img alt=\" \" src=\"/predownloaded/e3/d3/e3d3c930f4f93ca68c1e61630a2771472ecbd60a.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Second solution. Bruteforce all <span class=\"tex-span\"><i>x</i></span> values. For a fixed <span class=\"tex-span\"><i>x</i></span> values of <span class=\"tex-span\"><i>y</i></span> and <span class=\"tex-span\"><i>z</i></span> are defined uniquely: <span class=\"tex-span\"><i>y</i> = <i>b</i> - <i>x</i></span>, <span class=\"tex-span\"><i>z</i> = <i>a</i> - <i>x</i></span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(1) / <i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> Can you solve the problem for any vertex number <span class=\"tex-span\"><i>n</i></span>? When and how can such a graph be built?</p><h4><a href=\"/contest/343/problem/A\" title=\"Codeforces Round 200 (Div. 1)\">343A - Rational Resistance</a></h4><p>If a fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> can be obtained with <span class=\"tex-span\"><i>k</i></span> resistors, then it is simple to calculate that we can obtain fractions <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b6913fd8136f518e8a7898a9b759b74c4d483101.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/daf9572f0aa7677d7961c329e6277818df63bd9f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> with <span class=\"tex-span\"><i>k</i> + 1</span> resistors. So adding one resistor means performing one operation backwards in Euclidean algorithm. That means that the answer is equal to the number of steps in standard Euclidean algorithm.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e847ae811adbd761fa24db4ba7a6827e0806d670.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Бонус:</strong> At first we thought about the major problem (any two elements can be joined), but had a moment of eureka and got that the given problem unexpectedly naturally can be reduced to GCD. By the way, the result tree — <a href=\"https://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree\">http://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree</a>.</p><h4><a href=\"/contest/343/problem/B\" title=\"Codeforces Round 200 (Div. 1)\">343B - Alternating Current</a></h4><p>Let us solve the following problem first: we are given a string of symbols A and B. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>A</i></span>, then at the <span class=\"tex-span\"><i>i</i></span>-th step the upper wire (see figure) is being put over the lower wire. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>B</i></span>, the lower wire is being put over the upper wire at <span class=\"tex-span\"><i>i</i></span>-th step. Observe that if some two symbols <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are adjacent, we can untangle this place, throw the symbols out and obtain the string of length two symbols less. So the wires can be untangled iff the number of A's and B's in the string is the same. The given problem can be reduced to the described in a following fashion: in each odd position we change – to B and + to A. In each even position we change — to A and + to B. The reduction is correct, since on each even position the order of — and + are always swapped, and in each odd position their order is the same as in the beginning.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> If you are interested by this problem, you can learn about the braid theory <a href=\"https://en.wikipedia.org/wiki/Braid_theory\">http://en.wikipedia.org/wiki/Braid_theory</a> :] Fun fact: a harder version of this problem was planned already for Round #142, but the error in solution idea was found, and the problem was left to lay for almost a year.</p><h4><a href=\"/contest/343/problem/C\" title=\"Codeforces Round 200 (Div. 1)\">343C - Read Time</a></h4><p>Let's search the answer <span class=\"tex-span\"><i>t</i></span> with the binary search. Fix some value of <span class=\"tex-span\"><i>t</i></span>. Look at the first head from the left <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> that can read track <span class=\"tex-span\"><i>p</i>[0]</span>. If <span class=\"tex-span\"><i>p</i>[0] > <i>h</i>[<i>i</i>]</span>, then <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> goes to the right <span class=\"tex-span\"><i>t</i></span> seconds and reads all tracks on its way. Otherwise if <span class=\"tex-span\"><i>p</i>[0] ≤ <i>h</i>[<i>i</i>]</span>, then the head has two choices:</p> <ol> <li>go to the right <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> seconds, then <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> to the left and <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> again to the left;</li> <li>go to the left <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> seconds, then <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> to the right and <span class=\"tex-span\"><i>t</i> - 2·(<i>h</i>[<i>i</i>] - <i>p</i>[0])</span> again to the right.</li> </ol><p>Obviously, for <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> it is more advantageous to visit the track positioned as much as possible to the right. So we choose by <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7edc4f5554e1d173945160b7deaca92e61d7a755.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Then we move the pointer onto the first unread track, and repeat the algorithm for <span class=\"tex-span\"><i>h</i>[<i>i</i> + 1]</span>, and so on with each head.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/3342f24e1fd6ab939313f6d6278245c95d89544f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a>.</p><p><strong>Bonus:</strong> The problem is completely real, if the disk has only a single head, if we know, what tracks should be read; then the optimal algorithm chooses between the two choices described above. I and <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a> were listening this on a lecture, and created the given problem out of boredom ;]</p><h4><a href=\"/contest/343/problem/D\" title=\"Codeforces Round 200 (Div. 1)\">343D - Water Tree</a></h4><p>Let's learn how to color a whole subtree. For that enumerate all vertices in post-order DFS. Then each subtree covers a single continious vertex number segment. For each vertex we store the bounds of such segment for a subtree with a root in this vertex. Then to color a subtree means to color a segment in a segment tree.</p><p>Then create a segment tree that has a following property: if a vertex <span class=\"tex-span\"><i>v</i></span> was emptied, and is still empty, then this vertex is colored in the segment tree. In the beginning "empty" all the vertices. That is, color all the vertices in the segment tree. With this tree we can efficiently process the queries:</p> <ol> <li><p>Fill a vertex <span class=\"tex-span\"><i>v</i></span>. Clean the interval for the subtree of <span class=\"tex-span\"><i>v</i></span>. If before that some vertex of a subtree was empty, color the parent of <span class=\"tex-span\"><i>v</i></span>.</p></li> <li><p>Empty a vertex <span class=\"tex-span\"><i>v</i></span>. Color the vertex <span class=\"tex-span\"><i>v</i></span> in the segment tree.</p></li> <li><p>Reply whether a vertex <span class=\"tex-span\"><i>v</i></span> is filled. If in the segment tree at least one vertex is colored, then there is such a descendant of <span class=\"tex-span\"><i>v</i></span> that is empty now, so the vertex <span class=\"tex-span\"><i>v</i></span> is not filled.</p></li> </ol><p><a class=\"rated-user user-blue\" href=\"/profile/Shtrix\" title=\"Expert Shtrix\">Shtrix</a> noted that essentially the same solution can be implemented with only a single set.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fcb5cb34164112e0db4b3ef4b921f55df7ffb005.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> Some participants could see the similarities with a problem Ball Machine from BOI 2013, but the solutions to the both problems are quite different.</p><h4><a href=\"/contest/343/problem/E\" title=\"Codeforces Round 200 (Div. 1)\">343E - Pumping Stations</a></h4><p>In this problem we are asked to find such graph vertex permutation that maximizes the sum of the maximum flows sent between each two consequtive vertices in the permutation.</p><p>The problem can be solved with <a href=\"https://en.wikipedia.org/wiki/Gomory%E2%80%93Hu_tree\">Gomory-Hu</a> tree data structure. For a given weighted graph the tree has the following properties:</p> <ol> <li>The vertex set of the tree and the graph is the same.</li> <li>The maximum flow between vertices <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> in the tree is equal to the maximum flow in the graph.</li> </ol><p>Surprisingly, such a tree exists for any weighted graph, and can be built in <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. It appears that the answer to the problem is equal to the sum of the edge weights in this tree.</p><p>We prove this statement by induction on the number of the tree vertices. Pick the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> with the smallest weight in the tree. Consider that in an optimal permutation more than one path between two adjacent verteces in the permutation passes through this edge. Erase all these paths, then each of the <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> subtrees holds a set of disjoint remaining paths from the permutation. For each set, join all the paths in one chain, obtaining two chains. These chains we join by a path <span class=\"tex-span\"><i>s</i></span> that goes trough the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>. Thus we have built a permutation that is not worse than the considered one. For a path <span class=\"tex-span\"><i>s</i></span> the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> is the smallest, so the flow along this path is equal to the weight of this edge. It follows from the induction that in subtrees <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> the answer is equal to the sum of edges. By adding the weight of edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>, we get the desired result.</p><p>From the last paragraph it is clear how to build such a permutation: take the smallest edge, obtain two chains from the vertex subtrees recursively, and add them together to form a one chain. Since there are not many vertices, we can do this part in <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-orange\" href=\"/profile/Gerald\" title=\"Master Gerald\">Gerald</a>.</p><p><strong>Bonus:</strong> Shortly before the contest we decided to make the constraints more loyal, so some solution that find Gomory-Hu tree by finding flow <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> times also passed. We hope that nobody is particularly saddened by this fact. (;</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/343\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/344\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-8915\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"8860\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=200\" class=\"tag notice\" style=\"text-decoration: none;\">200</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+64</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8860#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8860#comments\">\n 53\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8931\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (43)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145823\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bipinb1994\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/91315/avatar/b4e2d8ac5b2569a3.jpg'/> </a>\n <div><a href=\"/profile/bipinb1994\" title=\"Expert bipinb1994\" class=\"rated-user user-blue\">bipinb1994</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 07:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145823\" href=\"?#comment-145823\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145823\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-15\"\r\n data-commentUserId=\"91315\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145823\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hai this was my first round in Codeforces. But my code was not accepted and it says that it was wrong with the 3rd test case. What i did was put a loop from 0 to n-1 and i checked ch[i][!=ch[i+1][0] then count++; else continue where 'ch' is the character array(2-D) whose size was Nx3 ...Is this algorithm completely wrong. As i said this was the first round here i did not understand what is wrong with this. If possible please do tell me what is wrong with this algorithm..:(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145823 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145823 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145823\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145863\" commentParentId=\"145823\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 14:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145863\" href=\"?#comment-145863\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145823\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145863\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145863\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please look at link <a href=\"//codeforces.com/contest/344/submission/4461494\">http://codeforces.com/contest/344/submission/4461494</a>. </p><p>The log says</p><p>Time: 0 ms, memory: 0 KB Verdict: WRONG_ANSWER Input 1 10 Output 0 Answer 1 Checker comment wrong answer 1st numbers differ — expected: '1', found: '0'</p><p>I believe this should be self explanatory. </p><p>Also it would help playing around with the system before trying to enter a rated match.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145863 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145863 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145863\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146026\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ka16\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ka16\" title=\"Pupil ka16\" class=\"rated-user user-green\">ka16</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 06:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146026\" href=\"?#comment-146026\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146026\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"12131\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146026\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody please clarify the two choices of head(s) in the solution of 343C-Read Time problem above? I couldn't understand it completely. Thank in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146026 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146026 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146026\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146037\" commentParentId=\"146026\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hriss95\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27396/avatar/d6cec8eac7bdbde3.jpg'/> </a>\n <div><a href=\"/profile/hriss95\" title=\"Expert hriss95\" class=\"rated-user user-blue\">hriss95</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 13:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146037\" href=\"?#comment-146037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146026\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146037\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"27396\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have to choose one of the two types moving: first to the right or first to the left. You have to use the one which covers more points to the right. Note that both types of moving cover the left point and that's why you have to take as much as points as you can to the right.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146037\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sorin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/sorin\" title=\"Expert sorin\" class=\"rated-user user-blue\">sorin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 12:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146034\" href=\"?#comment-146034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"124904\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody give me a hint for the bonus at Div2 — B? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146034\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146064\" commentParentId=\"146034\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 21:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146064\" href=\"?#comment-146064\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146034\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146064\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146064\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Think greedy ;]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146064 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146064 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146064\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"152157\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ghooo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2010/avatar/659a8aca8b12506a.jpg'/> </a>\n <div><a href=\"/profile/ghooo\" title=\"Master ghooo\" class=\"rated-user user-orange\">ghooo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/26/2013 08:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-152157\" href=\"?#comment-152157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"152157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2010\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-152157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>will the connections between the atoms be circular? like 1 <-> 2 <-> 3 <-> 4 <-> 5 ... n <-> 1 (again) ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-152157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-152157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-152157\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"521750\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/n0tred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1177564/avatar/a46e0281e87dd6c9.jpg'/> </a>\n <div><a href=\"/profile/n0tred\" title=\"Candidate Master n0tred\" class=\"rated-user user-violet\">n0tred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/25/2019 14:29\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-521750\" href=\"?#comment-521750\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"521750\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1177564\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-521750\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you give a better hint? (Maybe through a spoiler, I suppose)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-521750 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-521750 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-521750\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"523308\" commentParentId=\"521750\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/29/2019 09:36\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-523308\" href=\"?#comment-523308\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-521750\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"523308\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-523308\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the algorithm that continuously connects the vertex with the smallest degree with the vertex with the largest degree works (here by degree I mean the unconnected edges), and builds a connected graph. I think this can be proved by induction.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-523308 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-523308 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-523308\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146129\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 11:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146129\" href=\"?#comment-146129\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146129\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146129\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think there is an issue with Problem 343A — Rational Resistance. Here according to the editorial the answer to the ratio 6/5 would be 6(I have verified this with an accepted solution). But this ratio can be achieved with a resistance of 2 and 3 in parallel, which makes the number of resistors required equal to 5 which would imply the editorial and the system tests to be wrong.</p><p>Am I missing something here?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146129 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146129 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146129\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146259\" commentParentId=\"146129\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146259\" href=\"?#comment-146259\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146129\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146259\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146259\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think it's because the definition of <strong>one element</strong> only let you add <strong>one</strong> new unit resistor to another element</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146259 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146259 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146259\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146256\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146256\" href=\"?#comment-146256\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146256\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146256\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for the nice problems!</p><p>I just have a little question on 343C — Read Time. I use the same algorithm and get AC, but my algorithm is running at O(n log^2 n)... as for the step: "Then we move the pointer onto the first unread track" I use another binary search...</p><p>how can I implement the same algorithm with O(n log n) as said in editorial? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146256 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146256 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146256\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146269\" commentParentId=\"146256\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146269\" href=\"?#comment-146269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146256\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146269\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We hold two pointers: the first points at the first unread track from the left, and the second points at the first unused head so far. So we take this head and read with its help the maximum number of yet unread tracks (note that they are consequent and begin at the first pointer) according to the best of the two choices described in tutorial. Then we move the first pointer to the first yet unread track, and increment the second by one. Thus each pointer moves <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> times in this iteration of the binary search. Take also in consideration that some heads can be not used at all.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154161\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/s2k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146708/avatar/ec43946f377e5c64.jpg'/> </a>\n <div><a href=\"/profile/s2k\" title=\"Newbie s2k\" class=\"rated-user user-gray\">s2k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154161\" href=\"?#comment-154161\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154161\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146708\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154161\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi. I was just trying to solve problem A of division 2, but was unsuccessful after hours of effort. I eventually lost patience and decided to see the codes of others. I did understand what was going in the code, but couldn't figure out why this method was chosen in the first place. Can someone please help me understand the solution?</p><p>P.S. I'm a newbie with almost no prior knowledge about number theory. :$</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154161 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154161 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154161\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154163\" commentParentId=\"154161\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154163\" href=\"?#comment-154163\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-154161\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154163\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154163\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The number of islands is always one more than the number of splits between two neighboring dominoes. One can easily convince himself by looking at an image in the description.</p><p>There are 4 possibilities of neighboring dominoes:</p> <ul> <li>01 and 01: these attract, so they don't form a split and we don't care about them</li> <li>10 and 10: these attract, so they don't form a split and we don't care about them</li> <li>01 and 10: these don't attract, so they form a split</li> <li>10 and 01: these don't attract, so they form a split</li> </ul><p>So, we can deduce that we're only interested in neighboring dominoes that are different. This means we can just count the number of indexes i (1 <= i < N) such that s[i] != s[i+1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154163 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154163 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154163\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176652\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/S.Ged\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67184/avatar/a38f51555a40b56a.jpg'/> </a>\n <div><a href=\"/profile/S.Ged\" title=\"Candidate Master S.Ged\" class=\"rated-user user-violet\">S.Ged</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 04:10\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176652\" href=\"?#comment-176652\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"176652\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"176652\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"67184\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176652\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm confused by the first sentence of 343A — Rational Resistance tutorial</p><p>How can we obtain a/(a+b) with k+1 resistors if obatined a/b wiht k resistors ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176652 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176652 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176652\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176656\" commentParentId=\"176652\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/afrizal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/103639/avatar/206f6cf479b00060.jpg'/> </a>\n <div><a href=\"/profile/afrizal\" title=\"Expert afrizal\" class=\"rated-user user-blue\">afrizal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 07:05\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176656\" href=\"?#comment-176656\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176652\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"176656\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"103639\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176656\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Remember a/a is 1. If we have a/b resistance, put one more resistor parallel will give <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c1a16b55f7f10840909e0e5863ae3ce22e36c85b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176656 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176656 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176656\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"189636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/namikaze\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/227989/avatar/51e67e9e139a65f2.jpg'/> </a>\n <div><a href=\"/profile/namikaze\" title=\"Unrated, namikaze\" class=\"rated-user user-black\">namikaze</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/28/2014 15:45\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-189636\" href=\"?#comment-189636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"189636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"227989\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-189636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><code>adding one resistor means performing one operation backwards in Euclidean algorithm</code></p><p>Can someone explain this ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-189636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-189636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-189636\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"277029\" commentParentId=\"189636\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TomBombadil\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/106415/avatar/ed9d8ef375273241.jpg'/> </a>\n <div><a href=\"/profile/TomBombadil\" title=\"Specialist TomBombadil\" class=\"rated-user user-cyan\">TomBombadil</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2016 17:50\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-277029\" href=\"?#comment-277029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-189636\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"277029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"106415\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-277029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-orange\" href=\"/profile/gen\" title=\"Master gen\">gen</a> ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-277029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-277029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-277029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"351231\" commentParentId=\"277029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/R.A.X\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/122476/avatar/686763c746ac6e7b.jpg'/> </a>\n <div><a href=\"/profile/R.A.X\" title=\"Specialist R.A.X\" class=\"rated-user user-cyan\">R.A.X</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/27/2017 15:37\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-351231\" href=\"?#comment-351231\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-277029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"351231\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"351231\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"122476\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-351231\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Suppose you have resistance of(17/3), it could be formed by adding 1 + (14/3). If you have resistance of (3/17), it could be obtained by combining resistance of 1 and 3/14 in parallel.</p><p>In terms of variable, a/b could be obtained by 1 + resistors required to create ( a-b)/b resistance, assuming a>b. and a/b if b>a, could be obtained by 1 + resistors required to create ( a/(b-a) ).</p><p>Assuming a>b so resistorRequired(a,b) = 1 + resistorRequired(a-b,b).</p> <pre>resistorReqiored(a-b,b) = 1 + resistorRequired(a-2b,b)</pre><p>............</p> <pre>resistorRequired(a-(q-1)*b ,b) = 1 + resistorRequired(a-q*b,b)</pre><p>let say r = a-q*b == a%b now at this point, one resistance needs to be connected in parallel to the b/r resistance.</p><p>so again problem becomes calculating the requiredResistance(b,r) similar to above problem,</p><p>which is similar to the gcd problem.</p><p>Hope that helps.</p><p>Why it's like gcd(a,b) = gcd(a-b,b) =gcd(a-2b,b) .... </p><p>In case of gcd(a,b) = gcd(a-b,b)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-351231 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-351231 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-351231\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"393063\" commentParentId=\"351231\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ShafinKhadem\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/508696/avatar/1b5c8ae9cf51dc77.jpg'/> </a>\n <div><a href=\"/profile/ShafinKhadem\" title=\"Master ShafinKhadem\" class=\"rated-user user-orange\">ShafinKhadem</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/01/2017 09:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-393063\" href=\"?#comment-393063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-351231\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"393063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"508696\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-393063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for the nice explanation. Now the use of euclidian algorithm to solve this problem makes sense to me.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-393063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-393063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-393063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"220282\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CloverAsta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207753/avatar/45b71a38344fa830.jpg'/> </a>\n <div><a href=\"/profile/CloverAsta\" title=\"Expert CloverAsta\" class=\"rated-user user-blue\">CloverAsta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/01/2015 14:33\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-220282\" href=\"?#comment-220282\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"220282\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207753\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-220282\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain to me the solution for Problem C div2 I understand the transition from <code>k</code> to <code>k + 1</code> but the part about Euclidean algorithm is beyond me</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-220282 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-220282 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-220282\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"232136\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anajin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221428/avatar/b8f5979933e2ce3d.jpg'/> </a>\n <div><a href=\"/profile/anajin\" title=\"Expert anajin\" class=\"rated-user user-blue\">anajin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/03/2015 14:15\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-232136\" href=\"?#comment-232136\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"232136\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-232136\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>water tree can be solved by heavy-light decomposition...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-232136 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-232136 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-232136\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"454886\" commentParentId=\"232136\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cai_lw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/325977/avatar/202b61935928944.jpg'/> </a>\n <div><a href=\"/profile/cai_lw\" title=\"International Master cai_lw\" class=\"rated-user user-orange\">cai_lw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/30/2018 20:04\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-454886\" href=\"?#comment-454886\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-232136\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"454886\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"454886\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"325977\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-454886\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, this is almost the most standard problem for HLD. But their solution is cleverer and has lower time complexity. HLD is a little bit overkill for such simple operations.</p><p>Nevertheless, HLD can pass the test. My HLD solution passed in 900ms.</p><p>Also HLD was a relatively unknown algorithm to the CP community 5 years ago.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-454886 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-454886 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-454886\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"634570\" commentParentId=\"454886\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Suri429\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/776807/avatar/90399ec92a81320a.jpg'/> </a>\n <div><a href=\"/profile/Suri429\" title=\"Master Suri429\" class=\"rated-user user-orange\">Suri429</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2020 08:55\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-634570\" href=\"?#comment-634570\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-454886\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"634570\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"776807\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-634570\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain how to approach this with HLD? I am new to HLD, and not able to get any clue here. </p><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-634570 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-634570 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-634570\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"312598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/29/2016 12:31\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-312598\" href=\"?#comment-312598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"312598\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"312598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-312598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder why I did wrong in the implementation of lazy propagation for Div1D, could anyone kindly lend some help? </p><p><a href=\"//codeforces.com/contest/343/submission/20226349\">http://codeforces.com/contest/343/submission/20226349</a></p><p>Thanks in advance. =)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-312598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-312598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-312598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"357445\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anshulgarg19\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/anshulgarg19\" title=\"Pupil anshulgarg19\" class=\"rated-user user-green\">anshulgarg19</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/02/2017 20:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-357445\" href=\"?#comment-357445\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"357445\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"244328\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-357445\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Accepted solution for the problem 343A Rational Resistance would give 6 as the output for input a = 10 and b = 7 i.e.10/7. But, if we have 5 ohm and 2 ohm resistors in parallel, then we have the same resistance value 10/7. So minimum value should be 2 resistors for this case. Kindly explain if i am wrong in understanding the problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-357445 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-357445 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-357445\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360009\" commentParentId=\"357445\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/snehil10\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/351506/avatar/522f61633a219a3b.jpg'/> </a>\n <div><a href=\"/profile/snehil10\" title=\"Expert snehil10\" class=\"rated-user user-blue\">snehil10</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/14/2017 10:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360009\" href=\"?#comment-360009\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-357445\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"360009\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"351506\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360009\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have only 1-ohm resistors in the beginning. Thus it requires 5 1-ohm resistors to make a 5-ohm resistor, and 2 1-ohm resistors to make a 2-ohm resistor. So according to you answer is 7 and not 2.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360009 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360009 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360009\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371475\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rush_123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/rush_123\" title=\"Expert rush_123\" class=\"rated-user user-blue\">rush_123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/03/2017 17:42\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371475\" href=\"?#comment-371475\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"371475\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"439840\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371475\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 343D — Water Tree query 1 and 2 can be solved using a dfs to find in time and out time for every node and then using segment tree But what about 3rd query how to solve it?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371475 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371475 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371475\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"422269\" commentParentId=\"371475\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stringray\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/575608/avatar/2902babcf56868a2.jpg'/> </a>\n <div><a href=\"/profile/stringray\" title=\"Expert stringray\" class=\"rated-user user-blue\">stringray</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/28/2018 16:13\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-422269\" href=\"?#comment-422269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371475\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"422269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"575608\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-422269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yeah same question .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-422269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-422269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-422269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"437012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ragnarok_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ragnarok_\" title=\"Newbie ragnarok_\" class=\"rated-user user-gray\">ragnarok_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2018 08:59\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-437012\" href=\"?#comment-437012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"437012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"673189\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-437012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Q.343A can anybody explain me why min resistor for 199/200 is 200.....it can be also constructed using 101 resistors(1/2+1/4+1/5+1/40+1/50)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-437012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-437012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-437012\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"573631\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SLIMSHADYNICK\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/598862/avatar/7629f1b29f0fe807.jpg'/> </a>\n <div><a href=\"/profile/SLIMSHADYNICK\" title=\"Candidate Master SLIMSHADYNICK\" class=\"rated-user user-violet\">SLIMSHADYNICK</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2020 21:03\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-573631\" href=\"?#comment-573631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"573631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"598862\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-573631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>correct!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-573631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-573631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-573631\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587715\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pied-piper\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/754580/avatar/a6fb81d49bb96665.jpg'/> </a>\n <div><a href=\"/profile/pied-piper\" title=\"Expert pied-piper\" class=\"rated-user user-blue\">pied-piper</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/11/2020 16:14\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587715\" href=\"?#comment-587715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"587715\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"587715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"754580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It is because they are separate elements and hence they cannot be added together. Only an element and a 1 unit resistance can be added in series(or parallel)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587715\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"791297\" commentParentId=\"587715\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/15/2021 17:25\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-791297\" href=\"?#comment-791297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587715\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"791297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-791297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-791297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-791297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-791297\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"598229\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayank_ag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/644568/avatar/c1136e364e721d18.jpg'/> </a>\n <div><a href=\"/profile/mayank_ag\" title=\"Master mayank_ag\" class=\"rated-user user-orange\">mayank_ag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/05/2020 20:53\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-598229\" href=\"?#comment-598229\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"598229\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"644568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-598229\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>An alternate approach for solving D: Use of lazy segment tree over HLD & Euler path. For every filling, fill Euler path with current query number, and for emptying, fill HLD path from the root with query number. For queries, check which of the seg tree has high query number.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-598229 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-598229 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-598229\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"600816\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Asterix_11\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Asterix_11\" title=\"Pupil Asterix_11\" class=\"rated-user user-green\">Asterix_11</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/11/2020 00:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-600816\" href=\"?#comment-600816\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"600816\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1472760\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-600816\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem 344A</p> <pre><code>#include <iostream>\nusing namespace std;\nint main()\n{\n int a, i, b[100], ans;\n scanf("%d", &a);\n for(i = 0; i < a; ++i){\n scanf("%d", &b[i]);\n }\n ans = 1;\n for(i = 0; i < (a-1); ++i){\n if(b[i] != b[i + 1]){\n ++ans;}\n }\n printf("%d", ans);\n return 0;\n}\n</code></pre><p>This is my code, but I don't know how to improve it, so that the time limit won't be a problem anymore. Any help?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-600816 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-600816 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-600816\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752098\" commentParentId=\"600816\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 09:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752098\" href=\"?#comment-752098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-600816\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can make two variable for prev and current value and if they are not equal you can increment it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752098\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752075\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:25\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752075\" href=\"?#comment-752075\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752075\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752075\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Problem C, if more than one of the elements can be in parallel than for ratio 199 and 200 the answer given is 200. But we may solve this in 74. like 1/2+1/4+1/8+1/10+1/50.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752075 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752075 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752075\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752089\" commentParentId=\"752075\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752089\" href=\"?#comment-752089\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-752075\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752089\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752089\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Okay it would be like either + denominator to the numerator or + numerator to the denominator.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752089 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752089 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752089\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"946539\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mohsina_Shaikh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1396580/avatar/6f21616a2d8d578.jpg'/> </a>\n <div><a href=\"/profile/Mohsina_Shaikh\" title=\"Newbie Mohsina_Shaikh\" class=\"rated-user user-gray\">Mohsina_Shaikh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/24/2022 06:47\">13 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-946539\" href=\"?#comment-946539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"946539\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"946539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1396580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-946539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a> or <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a> or can anyone please explain <code>Alternating Current</code> Solution.Tried so hard but not able to understand it. A</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-946539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-946539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-946539\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"959164\" commentParentId=\"946539\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rishijoshi483\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2453886/avatar/1ecf48b346fe39d0.jpg'/> </a>\n <div><a href=\"/profile/rishijoshi483\" title=\"Expert rishijoshi483\" class=\"rated-user user-blue\">rishijoshi483</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/03/2022 09:44\">12 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-959164\" href=\"?#comment-959164\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-946539\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"959164\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2453886\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-959164\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try it using stack</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-959164 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-959164 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-959164\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"966651\" commentParentId=\"959164\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Yohajji\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2854745/avatar/b31d6e4c63852741.jpg'/> </a>\n <div><a href=\"/profile/Yohajji\" title=\"Newbie Yohajji\" class=\"rated-user user-gray\">Yohajji</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2022 13:35\">11 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-966651\" href=\"?#comment-966651\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-959164\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"966651\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2854745\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-966651\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>using the stack was a brilliant aproach, thank you </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-966651 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-966651 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-966651\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1039007\" commentParentId=\"966651\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AbdelrahmanMahallawy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3189297/avatar/6b2a1658ad37caa0.jpg'/> </a>\n <div><a href=\"/profile/AbdelrahmanMahallawy\" title=\"Newbie AbdelrahmanMahallawy\" class=\"rated-user user-gray\">AbdelrahmanMahallawy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/20/2023 03:36\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1039007\" href=\"?#comment-1039007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-966651\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1039007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3189297\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1039007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>anytime </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1039007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1039007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1039007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8931\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8931 = true;\r\nvar lastPreviewContent8931 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8931] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8931] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:23</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128748fcb8816ab',t:'MTY5NjcwNTk0My4yOTkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1739,"cells":{"problem_id":{"kind":"string","value":"343C"},"contest":{"kind":"string","value":"343"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Read Time"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Read Time</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike does not use slow hard disks. His modification of a hard drive has not one, but <span class=\"tex-span\"><i>n</i></span> different heads that can read data in parallel.</p><p>When viewed from the side, Mike's hard drive is an endless array of tracks. The tracks of the array are numbered from left to right with integers, starting with 1. In the initial state the <span class=\"tex-span\"><i>i</i></span>-th reading head is above the track number <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span>. For each of the reading heads, the hard drive's firmware can move the head exactly one track to the right or to the left, or leave it on the current track. During the operation each head's movement does not affect the movement of the other heads: the heads can change their relative order; there can be multiple reading heads above any of the tracks. A track is considered <span class=\"tex-font-style-underline\">read</span> if at least one head has visited this track. In particular, all of the tracks numbered <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>n</i></sub></span> have been read at the beginning of the operation.</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/74f1fe19c026065f690c4ac1646b3951b4afb6ea.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>Mike needs to read the data on <span class=\"tex-span\"><i>m</i></span> distinct tracks with numbers <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>m</i></sub></span>. Determine the minimum time the hard drive firmware needs to move the heads and read all the given tracks. Note that an arbitrary number of other tracks can also be read.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains two space-separated integers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i>, <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup></span>) — the number of disk heads and the number of tracks to read, accordingly. The second line contains <span class=\"tex-span\"><i>n</i></span> distinct integers <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span> in ascending order (<span class=\"tex-span\">1 ≤ <i>h</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">10</sup></span>, <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub> < <i>h</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>) — the initial positions of the heads. The third line contains <span class=\"tex-span\"><i>m</i></span> distinct integers <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> in ascending order (<span class=\"tex-span\">1 ≤ <i>p</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">10</sup></span>, <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub> < <i>p</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>) - the numbers of tracks to read.</p><p>Please, do not use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in С++. It is recommended to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single number — the minimum time required, in seconds, to read all the needed tracks.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 4<br/>2 5 6<br/>1 3 6 8<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>1 2 3<br/>1 2 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 2<br/>165<br/>142 200<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>81<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The first test coincides with the figure. In this case the given tracks can be read in 2 seconds in the following way: </p><ol> <li> during the first second move the 1-st head to the left and let it stay there; </li><li> move the second head to the left twice; </li><li> move the third head to the right twice (note that the 6-th track has already been read at the beginning). </li></ol><p>One cannot read the tracks in 1 second as the 3-rd head is at distance 2 from the 8-th track.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"143689b4a04e69573ee86842e93c969b\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"c35c56cdf057f72810b979434cacadcbf2ca863c\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='143689b4a04e69573ee86842e93c969b'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F343%2Fproblem%2FC%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='143689b4a04e69573ee86842e93c969b'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/343\">Codeforces Round 200 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='143689b4a04e69573ee86842e93c969b'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/343/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Binary search\">\r\n binary search\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Two pointers\">\r\n two pointers\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1900\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='143689b4a04e69573ee86842e93c969b'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3469\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='143689b4a04e69573ee86842e93c969b'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3469\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8851\" title=\"Codeforces Round #200\" target=\"_blank\">Codeforces Round #200</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1852:1853\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8860\" title=\"Codeforces Round #200 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1848:1849\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/343\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/343/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/343/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/343/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/343/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/343/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/343/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/343/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_9ba5c5ac0b89ca312762e459d1bfd3c84e587e48\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Read Time</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike does not use slow hard disks. His modification of a hard drive has not one, but <span class=\"tex-span\"><i>n</i></span> different heads that can read data in parallel.</p><p>When viewed from the side, Mike's hard drive is an endless array of tracks. The tracks of the array are numbered from left to right with integers, starting with 1. In the initial state the <span class=\"tex-span\"><i>i</i></span>-th reading head is above the track number <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span>. For each of the reading heads, the hard drive's firmware can move the head exactly one track to the right or to the left, or leave it on the current track. During the operation each head's movement does not affect the movement of the other heads: the heads can change their relative order; there can be multiple reading heads above any of the tracks. A track is considered <span class=\"tex-font-style-underline\">read</span> if at least one head has visited this track. In particular, all of the tracks numbered <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>n</i></sub></span> have been read at the beginning of the operation.</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/74f1fe19c026065f690c4ac1646b3951b4afb6ea.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>Mike needs to read the data on <span class=\"tex-span\"><i>m</i></span> distinct tracks with numbers <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>m</i></sub></span>. Determine the minimum time the hard drive firmware needs to move the heads and read all the given tracks. Note that an arbitrary number of other tracks can also be read.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains two space-separated integers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i>, <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup></span>) — the number of disk heads and the number of tracks to read, accordingly. The second line contains <span class=\"tex-span\"><i>n</i></span> distinct integers <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span> in ascending order (<span class=\"tex-span\">1 ≤ <i>h</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">10</sup></span>, <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub> < <i>h</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>) — the initial positions of the heads. The third line contains <span class=\"tex-span\"><i>m</i></span> distinct integers <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> in ascending order (<span class=\"tex-span\">1 ≤ <i>p</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">10</sup></span>, <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub> < <i>p</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>) - the numbers of tracks to read.</p><p>Please, do not use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in С++. It is recommended to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single number — the minimum time required, in seconds, to read all the needed tracks.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 4<br />2 5 6<br />1 3 6 8<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />1 2 3<br />1 2 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 2<br />165<br />142 200<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>81<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The first test coincides with the figure. In this case the given tracks can be read in 2 seconds in the following way: </p><ol> <li> during the first second move the 1-st head to the left and let it stay there; </li><li> move the second head to the left twice; </li><li> move the third head to the right twice (note that the 6-th track has already been read at the beginning). </li></ol><p>One cannot read the tracks in 1 second as the 3-rd head is at distance 2 from the 8-th track.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:36</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bd808b717a7d',t:'MTY5NjY0NjAxNi4xOTIwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Binary search\", \"Greedy algorithms\", \"Two pointers\"]"},"short_tags":{"kind":"string","value":"[\"binary search\", \"greedy\", \"two pointers\", \"*1900\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8860"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"21ba25574a0615e5dc71db6e32a512d8\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #200 Tutorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #200 Tutorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='21ba25574a0615e5dc71db6e32a512d8'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8860\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/gen\">gen</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gen\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gen\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gen\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gen\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gen\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gen\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gen\" style=\"text-decoration:none;color:black !important;\">gen's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8915\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8860\"> <p>Codeforces Round #200 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a>,\r\n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h4><a href=\"/contest/344/problem/A\" title=\"Codeforces Round 200 (Div. 2)\">344A - Magnets</a></h4><p>By the definition each block consists of a number of consequent and equally oriented dominoes. That means that in places where adjacent dominoes are not oriented equally, one block ends and another block starts. So, if there are <span class=\"tex-span\"><i>x</i></span> such places, the answer is equal to <span class=\"tex-span\"><i>x</i> + 1</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> The problem was created a day before the contest and filled in the last part of a physically flavoured DivII complect. :]</p><h4><a href=\"/contest/344/problem/B\" title=\"Codeforces Round 200 (Div. 2)\">344B - Simple Molecules</a></h4><p>First solution. First, the sum <span class=\"tex-span\"><i>a</i> + <i>b</i> + <i>c</i></span> should be even, since each bond adds 2 to the sum. Now let <span class=\"tex-span\"><i>x</i></span>, <span class=\"tex-span\"><i>y</i></span>, <span class=\"tex-span\"><i>z</i></span> be the number of bonds between 1st and 2nd, 2nd and 3rd, 3rd and 1st atoms, accordingly. So we have to solve the system <span class=\"tex-span\"><i>x</i> + <i>z</i> = <i>a</i></span>, <span class=\"tex-span\"><i>y</i> + <i>x</i> = <i>b</i></span>, <span class=\"tex-span\"><i>z</i> + <i>y</i> = <i>c</i></span>. Now observe that the solution to the system is the length of the tangents on the triangle with sides of length <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span> to its inscribed circle, and are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/2cee22ffa44dda3ce1b315e8cceef38c6288cf2c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1aed1c363b13d01e1b412b9cd3d5e34d19eb9c96.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/30fbfc651674588cadbee1fedd1e4b0d08d1ad4e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. If the problem asked only the possibility of building such a molecule, we could just check if there exists (possibly degenerate) triangle with sides <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span>.</p><p><img alt=\" \" src=\"/predownloaded/e3/d3/e3d3c930f4f93ca68c1e61630a2771472ecbd60a.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Second solution. Bruteforce all <span class=\"tex-span\"><i>x</i></span> values. For a fixed <span class=\"tex-span\"><i>x</i></span> values of <span class=\"tex-span\"><i>y</i></span> and <span class=\"tex-span\"><i>z</i></span> are defined uniquely: <span class=\"tex-span\"><i>y</i> = <i>b</i> - <i>x</i></span>, <span class=\"tex-span\"><i>z</i> = <i>a</i> - <i>x</i></span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(1) / <i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> Can you solve the problem for any vertex number <span class=\"tex-span\"><i>n</i></span>? When and how can such a graph be built?</p><h4><a href=\"/contest/343/problem/A\" title=\"Codeforces Round 200 (Div. 1)\">343A - Rational Resistance</a></h4><p>If a fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> can be obtained with <span class=\"tex-span\"><i>k</i></span> resistors, then it is simple to calculate that we can obtain fractions <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b6913fd8136f518e8a7898a9b759b74c4d483101.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/daf9572f0aa7677d7961c329e6277818df63bd9f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> with <span class=\"tex-span\"><i>k</i> + 1</span> resistors. So adding one resistor means performing one operation backwards in Euclidean algorithm. That means that the answer is equal to the number of steps in standard Euclidean algorithm.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e847ae811adbd761fa24db4ba7a6827e0806d670.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Бонус:</strong> At first we thought about the major problem (any two elements can be joined), but had a moment of eureka and got that the given problem unexpectedly naturally can be reduced to GCD. By the way, the result tree — <a href=\"https://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree\">http://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree</a>.</p><h4><a href=\"/contest/343/problem/B\" title=\"Codeforces Round 200 (Div. 1)\">343B - Alternating Current</a></h4><p>Let us solve the following problem first: we are given a string of symbols A and B. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>A</i></span>, then at the <span class=\"tex-span\"><i>i</i></span>-th step the upper wire (see figure) is being put over the lower wire. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>B</i></span>, the lower wire is being put over the upper wire at <span class=\"tex-span\"><i>i</i></span>-th step. Observe that if some two symbols <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are adjacent, we can untangle this place, throw the symbols out and obtain the string of length two symbols less. So the wires can be untangled iff the number of A's and B's in the string is the same. The given problem can be reduced to the described in a following fashion: in each odd position we change – to B and + to A. In each even position we change — to A and + to B. The reduction is correct, since on each even position the order of — and + are always swapped, and in each odd position their order is the same as in the beginning.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> If you are interested by this problem, you can learn about the braid theory <a href=\"https://en.wikipedia.org/wiki/Braid_theory\">http://en.wikipedia.org/wiki/Braid_theory</a> :] Fun fact: a harder version of this problem was planned already for Round #142, but the error in solution idea was found, and the problem was left to lay for almost a year.</p><h4><a href=\"/contest/343/problem/C\" title=\"Codeforces Round 200 (Div. 1)\">343C - Read Time</a></h4><p>Let's search the answer <span class=\"tex-span\"><i>t</i></span> with the binary search. Fix some value of <span class=\"tex-span\"><i>t</i></span>. Look at the first head from the left <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> that can read track <span class=\"tex-span\"><i>p</i>[0]</span>. If <span class=\"tex-span\"><i>p</i>[0] > <i>h</i>[<i>i</i>]</span>, then <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> goes to the right <span class=\"tex-span\"><i>t</i></span> seconds and reads all tracks on its way. Otherwise if <span class=\"tex-span\"><i>p</i>[0] ≤ <i>h</i>[<i>i</i>]</span>, then the head has two choices:</p> <ol> <li>go to the right <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> seconds, then <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> to the left and <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> again to the left;</li> <li>go to the left <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> seconds, then <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> to the right and <span class=\"tex-span\"><i>t</i> - 2·(<i>h</i>[<i>i</i>] - <i>p</i>[0])</span> again to the right.</li> </ol><p>Obviously, for <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> it is more advantageous to visit the track positioned as much as possible to the right. So we choose by <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7edc4f5554e1d173945160b7deaca92e61d7a755.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Then we move the pointer onto the first unread track, and repeat the algorithm for <span class=\"tex-span\"><i>h</i>[<i>i</i> + 1]</span>, and so on with each head.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/3342f24e1fd6ab939313f6d6278245c95d89544f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a>.</p><p><strong>Bonus:</strong> The problem is completely real, if the disk has only a single head, if we know, what tracks should be read; then the optimal algorithm chooses between the two choices described above. I and <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a> were listening this on a lecture, and created the given problem out of boredom ;]</p><h4><a href=\"/contest/343/problem/D\" title=\"Codeforces Round 200 (Div. 1)\">343D - Water Tree</a></h4><p>Let's learn how to color a whole subtree. For that enumerate all vertices in post-order DFS. Then each subtree covers a single continious vertex number segment. For each vertex we store the bounds of such segment for a subtree with a root in this vertex. Then to color a subtree means to color a segment in a segment tree.</p><p>Then create a segment tree that has a following property: if a vertex <span class=\"tex-span\"><i>v</i></span> was emptied, and is still empty, then this vertex is colored in the segment tree. In the beginning "empty" all the vertices. That is, color all the vertices in the segment tree. With this tree we can efficiently process the queries:</p> <ol> <li><p>Fill a vertex <span class=\"tex-span\"><i>v</i></span>. Clean the interval for the subtree of <span class=\"tex-span\"><i>v</i></span>. If before that some vertex of a subtree was empty, color the parent of <span class=\"tex-span\"><i>v</i></span>.</p></li> <li><p>Empty a vertex <span class=\"tex-span\"><i>v</i></span>. Color the vertex <span class=\"tex-span\"><i>v</i></span> in the segment tree.</p></li> <li><p>Reply whether a vertex <span class=\"tex-span\"><i>v</i></span> is filled. If in the segment tree at least one vertex is colored, then there is such a descendant of <span class=\"tex-span\"><i>v</i></span> that is empty now, so the vertex <span class=\"tex-span\"><i>v</i></span> is not filled.</p></li> </ol><p><a class=\"rated-user user-blue\" href=\"/profile/Shtrix\" title=\"Expert Shtrix\">Shtrix</a> noted that essentially the same solution can be implemented with only a single set.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fcb5cb34164112e0db4b3ef4b921f55df7ffb005.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> Some participants could see the similarities with a problem Ball Machine from BOI 2013, but the solutions to the both problems are quite different.</p><h4><a href=\"/contest/343/problem/E\" title=\"Codeforces Round 200 (Div. 1)\">343E - Pumping Stations</a></h4><p>In this problem we are asked to find such graph vertex permutation that maximizes the sum of the maximum flows sent between each two consequtive vertices in the permutation.</p><p>The problem can be solved with <a href=\"https://en.wikipedia.org/wiki/Gomory%E2%80%93Hu_tree\">Gomory-Hu</a> tree data structure. For a given weighted graph the tree has the following properties:</p> <ol> <li>The vertex set of the tree and the graph is the same.</li> <li>The maximum flow between vertices <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> in the tree is equal to the maximum flow in the graph.</li> </ol><p>Surprisingly, such a tree exists for any weighted graph, and can be built in <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. It appears that the answer to the problem is equal to the sum of the edge weights in this tree.</p><p>We prove this statement by induction on the number of the tree vertices. Pick the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> with the smallest weight in the tree. Consider that in an optimal permutation more than one path between two adjacent verteces in the permutation passes through this edge. Erase all these paths, then each of the <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> subtrees holds a set of disjoint remaining paths from the permutation. For each set, join all the paths in one chain, obtaining two chains. These chains we join by a path <span class=\"tex-span\"><i>s</i></span> that goes trough the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>. Thus we have built a permutation that is not worse than the considered one. For a path <span class=\"tex-span\"><i>s</i></span> the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> is the smallest, so the flow along this path is equal to the weight of this edge. It follows from the induction that in subtrees <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> the answer is equal to the sum of edges. By adding the weight of edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>, we get the desired result.</p><p>From the last paragraph it is clear how to build such a permutation: take the smallest edge, obtain two chains from the vertex subtrees recursively, and add them together to form a one chain. Since there are not many vertices, we can do this part in <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-orange\" href=\"/profile/Gerald\" title=\"Master Gerald\">Gerald</a>.</p><p><strong>Bonus:</strong> Shortly before the contest we decided to make the constraints more loyal, so some solution that find Gomory-Hu tree by finding flow <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> times also passed. We hope that nobody is particularly saddened by this fact. (;</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/343\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/344\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-8915\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"8860\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=200\" class=\"tag notice\" style=\"text-decoration: none;\">200</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+64</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8860#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8860#comments\">\n 53\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8931\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (43)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145823\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bipinb1994\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/91315/avatar/b4e2d8ac5b2569a3.jpg'/> </a>\n <div><a href=\"/profile/bipinb1994\" title=\"Expert bipinb1994\" class=\"rated-user user-blue\">bipinb1994</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 07:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145823\" href=\"?#comment-145823\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145823\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-15\"\r\n data-commentUserId=\"91315\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145823\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hai this was my first round in Codeforces. But my code was not accepted and it says that it was wrong with the 3rd test case. What i did was put a loop from 0 to n-1 and i checked ch[i][!=ch[i+1][0] then count++; else continue where 'ch' is the character array(2-D) whose size was Nx3 ...Is this algorithm completely wrong. As i said this was the first round here i did not understand what is wrong with this. If possible please do tell me what is wrong with this algorithm..:(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145823 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145823 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145823\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145863\" commentParentId=\"145823\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 14:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145863\" href=\"?#comment-145863\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145823\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145863\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145863\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please look at link <a href=\"//codeforces.com/contest/344/submission/4461494\">http://codeforces.com/contest/344/submission/4461494</a>. </p><p>The log says</p><p>Time: 0 ms, memory: 0 KB Verdict: WRONG_ANSWER Input 1 10 Output 0 Answer 1 Checker comment wrong answer 1st numbers differ — expected: '1', found: '0'</p><p>I believe this should be self explanatory. </p><p>Also it would help playing around with the system before trying to enter a rated match.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145863 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145863 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145863\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146026\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ka16\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ka16\" title=\"Pupil ka16\" class=\"rated-user user-green\">ka16</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 06:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146026\" href=\"?#comment-146026\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146026\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"12131\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146026\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody please clarify the two choices of head(s) in the solution of 343C-Read Time problem above? I couldn't understand it completely. Thank in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146026 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146026 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146026\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146037\" commentParentId=\"146026\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hriss95\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27396/avatar/d6cec8eac7bdbde3.jpg'/> </a>\n <div><a href=\"/profile/hriss95\" title=\"Expert hriss95\" class=\"rated-user user-blue\">hriss95</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 13:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146037\" href=\"?#comment-146037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146026\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146037\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"27396\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have to choose one of the two types moving: first to the right or first to the left. You have to use the one which covers more points to the right. Note that both types of moving cover the left point and that's why you have to take as much as points as you can to the right.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146037\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sorin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/sorin\" title=\"Expert sorin\" class=\"rated-user user-blue\">sorin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 12:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146034\" href=\"?#comment-146034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"124904\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody give me a hint for the bonus at Div2 — B? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146034\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146064\" commentParentId=\"146034\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 21:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146064\" href=\"?#comment-146064\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146034\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146064\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146064\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Think greedy ;]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146064 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146064 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146064\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"152157\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ghooo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2010/avatar/659a8aca8b12506a.jpg'/> </a>\n <div><a href=\"/profile/ghooo\" title=\"Master ghooo\" class=\"rated-user user-orange\">ghooo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/26/2013 08:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-152157\" href=\"?#comment-152157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"152157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2010\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-152157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>will the connections between the atoms be circular? like 1 <-> 2 <-> 3 <-> 4 <-> 5 ... n <-> 1 (again) ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-152157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-152157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-152157\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"521750\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/n0tred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1177564/avatar/a46e0281e87dd6c9.jpg'/> </a>\n <div><a href=\"/profile/n0tred\" title=\"Candidate Master n0tred\" class=\"rated-user user-violet\">n0tred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/25/2019 14:29\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-521750\" href=\"?#comment-521750\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"521750\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1177564\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-521750\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you give a better hint? (Maybe through a spoiler, I suppose)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-521750 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-521750 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-521750\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"523308\" commentParentId=\"521750\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/29/2019 09:36\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-523308\" href=\"?#comment-523308\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-521750\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"523308\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-523308\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the algorithm that continuously connects the vertex with the smallest degree with the vertex with the largest degree works (here by degree I mean the unconnected edges), and builds a connected graph. I think this can be proved by induction.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-523308 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-523308 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-523308\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146129\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 11:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146129\" href=\"?#comment-146129\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146129\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146129\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think there is an issue with Problem 343A — Rational Resistance. Here according to the editorial the answer to the ratio 6/5 would be 6(I have verified this with an accepted solution). But this ratio can be achieved with a resistance of 2 and 3 in parallel, which makes the number of resistors required equal to 5 which would imply the editorial and the system tests to be wrong.</p><p>Am I missing something here?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146129 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146129 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146129\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146259\" commentParentId=\"146129\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146259\" href=\"?#comment-146259\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146129\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146259\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146259\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think it's because the definition of <strong>one element</strong> only let you add <strong>one</strong> new unit resistor to another element</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146259 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146259 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146259\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146256\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146256\" href=\"?#comment-146256\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146256\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146256\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for the nice problems!</p><p>I just have a little question on 343C — Read Time. I use the same algorithm and get AC, but my algorithm is running at O(n log^2 n)... as for the step: "Then we move the pointer onto the first unread track" I use another binary search...</p><p>how can I implement the same algorithm with O(n log n) as said in editorial? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146256 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146256 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146256\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146269\" commentParentId=\"146256\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146269\" href=\"?#comment-146269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146256\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146269\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We hold two pointers: the first points at the first unread track from the left, and the second points at the first unused head so far. So we take this head and read with its help the maximum number of yet unread tracks (note that they are consequent and begin at the first pointer) according to the best of the two choices described in tutorial. Then we move the first pointer to the first yet unread track, and increment the second by one. Thus each pointer moves <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> times in this iteration of the binary search. Take also in consideration that some heads can be not used at all.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154161\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/s2k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146708/avatar/ec43946f377e5c64.jpg'/> </a>\n <div><a href=\"/profile/s2k\" title=\"Newbie s2k\" class=\"rated-user user-gray\">s2k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154161\" href=\"?#comment-154161\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154161\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146708\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154161\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi. I was just trying to solve problem A of division 2, but was unsuccessful after hours of effort. I eventually lost patience and decided to see the codes of others. I did understand what was going in the code, but couldn't figure out why this method was chosen in the first place. Can someone please help me understand the solution?</p><p>P.S. I'm a newbie with almost no prior knowledge about number theory. :$</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154161 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154161 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154161\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154163\" commentParentId=\"154161\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154163\" href=\"?#comment-154163\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-154161\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154163\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154163\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The number of islands is always one more than the number of splits between two neighboring dominoes. One can easily convince himself by looking at an image in the description.</p><p>There are 4 possibilities of neighboring dominoes:</p> <ul> <li>01 and 01: these attract, so they don't form a split and we don't care about them</li> <li>10 and 10: these attract, so they don't form a split and we don't care about them</li> <li>01 and 10: these don't attract, so they form a split</li> <li>10 and 01: these don't attract, so they form a split</li> </ul><p>So, we can deduce that we're only interested in neighboring dominoes that are different. This means we can just count the number of indexes i (1 <= i < N) such that s[i] != s[i+1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154163 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154163 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154163\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176652\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/S.Ged\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67184/avatar/a38f51555a40b56a.jpg'/> </a>\n <div><a href=\"/profile/S.Ged\" title=\"Candidate Master S.Ged\" class=\"rated-user user-violet\">S.Ged</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 04:10\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176652\" href=\"?#comment-176652\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"176652\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"176652\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"67184\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176652\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm confused by the first sentence of 343A — Rational Resistance tutorial</p><p>How can we obtain a/(a+b) with k+1 resistors if obatined a/b wiht k resistors ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176652 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176652 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176652\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176656\" commentParentId=\"176652\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/afrizal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/103639/avatar/206f6cf479b00060.jpg'/> </a>\n <div><a href=\"/profile/afrizal\" title=\"Expert afrizal\" class=\"rated-user user-blue\">afrizal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 07:05\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176656\" href=\"?#comment-176656\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176652\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"176656\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"103639\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176656\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Remember a/a is 1. If we have a/b resistance, put one more resistor parallel will give <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c1a16b55f7f10840909e0e5863ae3ce22e36c85b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176656 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176656 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176656\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"189636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/namikaze\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/227989/avatar/51e67e9e139a65f2.jpg'/> </a>\n <div><a href=\"/profile/namikaze\" title=\"Unrated, namikaze\" class=\"rated-user user-black\">namikaze</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/28/2014 15:45\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-189636\" href=\"?#comment-189636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"189636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"227989\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-189636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><code>adding one resistor means performing one operation backwards in Euclidean algorithm</code></p><p>Can someone explain this ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-189636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-189636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-189636\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"277029\" commentParentId=\"189636\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TomBombadil\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/106415/avatar/ed9d8ef375273241.jpg'/> </a>\n <div><a href=\"/profile/TomBombadil\" title=\"Specialist TomBombadil\" class=\"rated-user user-cyan\">TomBombadil</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2016 17:50\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-277029\" href=\"?#comment-277029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-189636\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"277029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"106415\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-277029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-orange\" href=\"/profile/gen\" title=\"Master gen\">gen</a> ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-277029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-277029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-277029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"351231\" commentParentId=\"277029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/R.A.X\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/122476/avatar/686763c746ac6e7b.jpg'/> </a>\n <div><a href=\"/profile/R.A.X\" title=\"Specialist R.A.X\" class=\"rated-user user-cyan\">R.A.X</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/27/2017 15:37\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-351231\" href=\"?#comment-351231\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-277029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"351231\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"351231\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"122476\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-351231\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Suppose you have resistance of(17/3), it could be formed by adding 1 + (14/3). If you have resistance of (3/17), it could be obtained by combining resistance of 1 and 3/14 in parallel.</p><p>In terms of variable, a/b could be obtained by 1 + resistors required to create ( a-b)/b resistance, assuming a>b. and a/b if b>a, could be obtained by 1 + resistors required to create ( a/(b-a) ).</p><p>Assuming a>b so resistorRequired(a,b) = 1 + resistorRequired(a-b,b).</p> <pre>resistorReqiored(a-b,b) = 1 + resistorRequired(a-2b,b)</pre><p>............</p> <pre>resistorRequired(a-(q-1)*b ,b) = 1 + resistorRequired(a-q*b,b)</pre><p>let say r = a-q*b == a%b now at this point, one resistance needs to be connected in parallel to the b/r resistance.</p><p>so again problem becomes calculating the requiredResistance(b,r) similar to above problem,</p><p>which is similar to the gcd problem.</p><p>Hope that helps.</p><p>Why it's like gcd(a,b) = gcd(a-b,b) =gcd(a-2b,b) .... </p><p>In case of gcd(a,b) = gcd(a-b,b)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-351231 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-351231 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-351231\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"393063\" commentParentId=\"351231\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ShafinKhadem\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/508696/avatar/1b5c8ae9cf51dc77.jpg'/> </a>\n <div><a href=\"/profile/ShafinKhadem\" title=\"Master ShafinKhadem\" class=\"rated-user user-orange\">ShafinKhadem</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/01/2017 09:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-393063\" href=\"?#comment-393063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-351231\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"393063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"508696\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-393063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for the nice explanation. Now the use of euclidian algorithm to solve this problem makes sense to me.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-393063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-393063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-393063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"220282\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CloverAsta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207753/avatar/45b71a38344fa830.jpg'/> </a>\n <div><a href=\"/profile/CloverAsta\" title=\"Expert CloverAsta\" class=\"rated-user user-blue\">CloverAsta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/01/2015 14:33\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-220282\" href=\"?#comment-220282\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"220282\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207753\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-220282\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain to me the solution for Problem C div2 I understand the transition from <code>k</code> to <code>k + 1</code> but the part about Euclidean algorithm is beyond me</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-220282 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-220282 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-220282\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"232136\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anajin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221428/avatar/b8f5979933e2ce3d.jpg'/> </a>\n <div><a href=\"/profile/anajin\" title=\"Expert anajin\" class=\"rated-user user-blue\">anajin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/03/2015 14:15\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-232136\" href=\"?#comment-232136\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"232136\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-232136\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>water tree can be solved by heavy-light decomposition...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-232136 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-232136 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-232136\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"454886\" commentParentId=\"232136\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cai_lw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/325977/avatar/202b61935928944.jpg'/> </a>\n <div><a href=\"/profile/cai_lw\" title=\"International Master cai_lw\" class=\"rated-user user-orange\">cai_lw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/30/2018 20:04\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-454886\" href=\"?#comment-454886\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-232136\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"454886\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"454886\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"325977\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-454886\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, this is almost the most standard problem for HLD. But their solution is cleverer and has lower time complexity. HLD is a little bit overkill for such simple operations.</p><p>Nevertheless, HLD can pass the test. My HLD solution passed in 900ms.</p><p>Also HLD was a relatively unknown algorithm to the CP community 5 years ago.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-454886 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-454886 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-454886\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"634570\" commentParentId=\"454886\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Suri429\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/776807/avatar/90399ec92a81320a.jpg'/> </a>\n <div><a href=\"/profile/Suri429\" title=\"Master Suri429\" class=\"rated-user user-orange\">Suri429</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2020 08:55\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-634570\" href=\"?#comment-634570\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-454886\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"634570\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"776807\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-634570\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain how to approach this with HLD? I am new to HLD, and not able to get any clue here. </p><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-634570 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-634570 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-634570\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"312598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/29/2016 12:31\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-312598\" href=\"?#comment-312598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"312598\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"312598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-312598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder why I did wrong in the implementation of lazy propagation for Div1D, could anyone kindly lend some help? </p><p><a href=\"//codeforces.com/contest/343/submission/20226349\">http://codeforces.com/contest/343/submission/20226349</a></p><p>Thanks in advance. =)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-312598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-312598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-312598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"357445\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anshulgarg19\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/anshulgarg19\" title=\"Pupil anshulgarg19\" class=\"rated-user user-green\">anshulgarg19</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/02/2017 20:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-357445\" href=\"?#comment-357445\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"357445\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"244328\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-357445\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Accepted solution for the problem 343A Rational Resistance would give 6 as the output for input a = 10 and b = 7 i.e.10/7. But, if we have 5 ohm and 2 ohm resistors in parallel, then we have the same resistance value 10/7. So minimum value should be 2 resistors for this case. Kindly explain if i am wrong in understanding the problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-357445 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-357445 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-357445\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360009\" commentParentId=\"357445\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/snehil10\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/351506/avatar/522f61633a219a3b.jpg'/> </a>\n <div><a href=\"/profile/snehil10\" title=\"Expert snehil10\" class=\"rated-user user-blue\">snehil10</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/14/2017 10:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360009\" href=\"?#comment-360009\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-357445\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"360009\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"351506\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360009\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have only 1-ohm resistors in the beginning. Thus it requires 5 1-ohm resistors to make a 5-ohm resistor, and 2 1-ohm resistors to make a 2-ohm resistor. So according to you answer is 7 and not 2.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360009 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360009 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360009\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371475\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rush_123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/rush_123\" title=\"Expert rush_123\" class=\"rated-user user-blue\">rush_123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/03/2017 17:42\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371475\" href=\"?#comment-371475\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"371475\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"439840\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371475\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 343D — Water Tree query 1 and 2 can be solved using a dfs to find in time and out time for every node and then using segment tree But what about 3rd query how to solve it?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371475 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371475 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371475\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"422269\" commentParentId=\"371475\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stringray\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/575608/avatar/2902babcf56868a2.jpg'/> </a>\n <div><a href=\"/profile/stringray\" title=\"Expert stringray\" class=\"rated-user user-blue\">stringray</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/28/2018 16:13\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-422269\" href=\"?#comment-422269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371475\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"422269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"575608\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-422269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yeah same question .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-422269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-422269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-422269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"437012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ragnarok_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ragnarok_\" title=\"Newbie ragnarok_\" class=\"rated-user user-gray\">ragnarok_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2018 08:59\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-437012\" href=\"?#comment-437012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"437012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"673189\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-437012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Q.343A can anybody explain me why min resistor for 199/200 is 200.....it can be also constructed using 101 resistors(1/2+1/4+1/5+1/40+1/50)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-437012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-437012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-437012\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"573631\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SLIMSHADYNICK\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/598862/avatar/7629f1b29f0fe807.jpg'/> </a>\n <div><a href=\"/profile/SLIMSHADYNICK\" title=\"Candidate Master SLIMSHADYNICK\" class=\"rated-user user-violet\">SLIMSHADYNICK</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2020 21:03\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-573631\" href=\"?#comment-573631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"573631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"598862\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-573631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>correct!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-573631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-573631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-573631\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587715\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pied-piper\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/754580/avatar/a6fb81d49bb96665.jpg'/> </a>\n <div><a href=\"/profile/pied-piper\" title=\"Expert pied-piper\" class=\"rated-user user-blue\">pied-piper</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/11/2020 16:14\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587715\" href=\"?#comment-587715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"587715\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"587715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"754580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It is because they are separate elements and hence they cannot be added together. Only an element and a 1 unit resistance can be added in series(or parallel)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587715\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"791297\" commentParentId=\"587715\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/15/2021 17:25\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-791297\" href=\"?#comment-791297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587715\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"791297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-791297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-791297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-791297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-791297\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"598229\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayank_ag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/644568/avatar/c1136e364e721d18.jpg'/> </a>\n <div><a href=\"/profile/mayank_ag\" title=\"Master mayank_ag\" class=\"rated-user user-orange\">mayank_ag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/05/2020 20:53\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-598229\" href=\"?#comment-598229\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"598229\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"644568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-598229\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>An alternate approach for solving D: Use of lazy segment tree over HLD & Euler path. For every filling, fill Euler path with current query number, and for emptying, fill HLD path from the root with query number. For queries, check which of the seg tree has high query number.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-598229 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-598229 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-598229\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"600816\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Asterix_11\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Asterix_11\" title=\"Pupil Asterix_11\" class=\"rated-user user-green\">Asterix_11</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/11/2020 00:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-600816\" href=\"?#comment-600816\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"600816\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1472760\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-600816\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem 344A</p> <pre><code>#include <iostream>\nusing namespace std;\nint main()\n{\n int a, i, b[100], ans;\n scanf("%d", &a);\n for(i = 0; i < a; ++i){\n scanf("%d", &b[i]);\n }\n ans = 1;\n for(i = 0; i < (a-1); ++i){\n if(b[i] != b[i + 1]){\n ++ans;}\n }\n printf("%d", ans);\n return 0;\n}\n</code></pre><p>This is my code, but I don't know how to improve it, so that the time limit won't be a problem anymore. Any help?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-600816 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-600816 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-600816\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752098\" commentParentId=\"600816\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 09:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752098\" href=\"?#comment-752098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-600816\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can make two variable for prev and current value and if they are not equal you can increment it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752098\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752075\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:25\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752075\" href=\"?#comment-752075\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752075\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752075\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Problem C, if more than one of the elements can be in parallel than for ratio 199 and 200 the answer given is 200. But we may solve this in 74. like 1/2+1/4+1/8+1/10+1/50.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752075 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752075 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752075\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752089\" commentParentId=\"752075\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752089\" href=\"?#comment-752089\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-752075\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752089\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752089\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Okay it would be like either + denominator to the numerator or + numerator to the denominator.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752089 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752089 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752089\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"946539\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mohsina_Shaikh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1396580/avatar/6f21616a2d8d578.jpg'/> </a>\n <div><a href=\"/profile/Mohsina_Shaikh\" title=\"Newbie Mohsina_Shaikh\" class=\"rated-user user-gray\">Mohsina_Shaikh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/24/2022 06:47\">13 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-946539\" href=\"?#comment-946539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"946539\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"946539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1396580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-946539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a> or <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a> or can anyone please explain <code>Alternating Current</code> Solution.Tried so hard but not able to understand it. A</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-946539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-946539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-946539\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"959164\" commentParentId=\"946539\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rishijoshi483\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2453886/avatar/1ecf48b346fe39d0.jpg'/> </a>\n <div><a href=\"/profile/rishijoshi483\" title=\"Expert rishijoshi483\" class=\"rated-user user-blue\">rishijoshi483</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/03/2022 09:44\">12 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-959164\" href=\"?#comment-959164\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-946539\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"959164\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2453886\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-959164\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try it using stack</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-959164 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-959164 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-959164\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"966651\" commentParentId=\"959164\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Yohajji\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2854745/avatar/b31d6e4c63852741.jpg'/> </a>\n <div><a href=\"/profile/Yohajji\" title=\"Newbie Yohajji\" class=\"rated-user user-gray\">Yohajji</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2022 13:35\">11 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-966651\" href=\"?#comment-966651\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-959164\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"966651\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2854745\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-966651\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>using the stack was a brilliant aproach, thank you </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-966651 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-966651 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-966651\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1039007\" commentParentId=\"966651\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AbdelrahmanMahallawy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3189297/avatar/6b2a1658ad37caa0.jpg'/> </a>\n <div><a href=\"/profile/AbdelrahmanMahallawy\" title=\"Newbie AbdelrahmanMahallawy\" class=\"rated-user user-gray\">AbdelrahmanMahallawy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/20/2023 03:36\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1039007\" href=\"?#comment-1039007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-966651\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1039007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3189297\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1039007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>anytime </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1039007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1039007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1039007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8931\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8931 = true;\r\nvar lastPreviewContent8931 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8931] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8931] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:23</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128748fcb8816ab',t:'MTY5NjcwNTk0My4yOTkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1740,"cells":{"problem_id":{"kind":"string","value":"343D"},"contest":{"kind":"string","value":"343"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Water Tree"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Water Tree</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>4 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike has constructed a rooted tree, which consists of <span class=\"tex-span\"><i>n</i></span> vertices. Each vertex is a reservoir which can be either empty or filled with water.</p><p>The vertices of the tree are numbered from 1 to <span class=\"tex-span\"><i>n</i></span> with the root at vertex 1. For each vertex, the reservoirs of its children are located below the reservoir of this vertex, and the vertex is connected with each of the children by a pipe through which water can flow downwards.</p><p>Mike wants to do the following operations with the tree: </p><ol> <li> Fill vertex <span class=\"tex-span\"><i>v</i></span> with water. Then <span class=\"tex-span\"><i>v</i></span> and all its children are filled with water. </li><li> Empty vertex <span class=\"tex-span\"><i>v</i></span>. Then <span class=\"tex-span\"><i>v</i></span> and all its ancestors are emptied. </li><li> Determine whether vertex <span class=\"tex-span\"><i>v</i></span> is filled with water at the moment. </li></ol> Initially all vertices of the tree are empty.<p>Mike has already compiled a full list of operations that he wants to perform in order. Before experimenting with the tree Mike decided to run the list through a simulation. Help Mike determine what results will he get after performing all the operations.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 500000</span>) — the number of vertices in the tree. Each of the following <span class=\"tex-span\"><i>n</i> - 1</span> lines contains two space-separated numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>) — the edges of the tree.</p><p>The next line contains a number <span class=\"tex-span\"><i>q</i></span> (<span class=\"tex-span\">1 ≤ <i>q</i> ≤ 500000</span>) — the number of operations to perform. Each of the following <span class=\"tex-span\"><i>q</i></span> lines contains two space-separated numbers <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>c</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 3</span>), <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>v</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>), where <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> is the operation type (according to the numbering given in the statement), and <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> is the vertex on which the operation is performed.</p><p>It is guaranteed that the given graph is a tree.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each type 3 operation print 1 on a separate line if the vertex is full, and 0 if the vertex is empty. Print the answers to queries in the order in which the queries are given in the input.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>1 2<br/>5 1<br/>2 3<br/>4 2<br/>12<br/>1 1<br/>2 3<br/>3 1<br/>3 2<br/>3 3<br/>3 4<br/>1 2<br/>2 4<br/>3 1<br/>3 3<br/>3 4<br/>3 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/>0<br/>0<br/>1<br/>0<br/>1<br/>0<br/>1<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"30cabd482a67b8baf8e8963e96a18c5a\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"c35c56cdf057f72810b979434cacadcbf2ca863c\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='30cabd482a67b8baf8e8963e96a18c5a'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F343%2Fproblem%2FD%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='30cabd482a67b8baf8e8963e96a18c5a'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/343\">Codeforces Round 200 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='30cabd482a67b8baf8e8963e96a18c5a'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/343/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Heaps, binary search trees, segment trees, hash tables, etc\">\r\n data structures\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dfs and similar\">\r\n dfs and similar\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Graphs\">\r\n graphs\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Trees\">\r\n trees\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2100\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='30cabd482a67b8baf8e8963e96a18c5a'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3470\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='30cabd482a67b8baf8e8963e96a18c5a'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3470\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8851\" title=\"Codeforces Round #200\" target=\"_blank\">Codeforces Round #200</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1852:1853\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8860\" title=\"Codeforces Round #200 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1848:1849\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/343\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/343/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/343/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/343/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/343/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/343/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/343/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/343/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_e96c06b5eb9d342faaeb68d51923923da047b882\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Water Tree</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>4 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike has constructed a rooted tree, which consists of <span class=\"tex-span\"><i>n</i></span> vertices. Each vertex is a reservoir which can be either empty or filled with water.</p><p>The vertices of the tree are numbered from 1 to <span class=\"tex-span\"><i>n</i></span> with the root at vertex 1. For each vertex, the reservoirs of its children are located below the reservoir of this vertex, and the vertex is connected with each of the children by a pipe through which water can flow downwards.</p><p>Mike wants to do the following operations with the tree: </p><ol> <li> Fill vertex <span class=\"tex-span\"><i>v</i></span> with water. Then <span class=\"tex-span\"><i>v</i></span> and all its children are filled with water. </li><li> Empty vertex <span class=\"tex-span\"><i>v</i></span>. Then <span class=\"tex-span\"><i>v</i></span> and all its ancestors are emptied. </li><li> Determine whether vertex <span class=\"tex-span\"><i>v</i></span> is filled with water at the moment. </li></ol> Initially all vertices of the tree are empty.<p>Mike has already compiled a full list of operations that he wants to perform in order. Before experimenting with the tree Mike decided to run the list through a simulation. Help Mike determine what results will he get after performing all the operations.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 500000</span>) — the number of vertices in the tree. Each of the following <span class=\"tex-span\"><i>n</i> - 1</span> lines contains two space-separated numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>) — the edges of the tree.</p><p>The next line contains a number <span class=\"tex-span\"><i>q</i></span> (<span class=\"tex-span\">1 ≤ <i>q</i> ≤ 500000</span>) — the number of operations to perform. Each of the following <span class=\"tex-span\"><i>q</i></span> lines contains two space-separated numbers <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>c</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 3</span>), <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>v</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>), where <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> is the operation type (according to the numbering given in the statement), and <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> is the vertex on which the operation is performed.</p><p>It is guaranteed that the given graph is a tree.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each type 3 operation print 1 on a separate line if the vertex is full, and 0 if the vertex is empty. Print the answers to queries in the order in which the queries are given in the input.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />1 2<br />5 1<br />2 3<br />4 2<br />12<br />1 1<br />2 3<br />3 1<br />3 2<br />3 3<br />3 4<br />1 2<br />2 4<br />3 1<br />3 3<br />3 4<br />3 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br />0<br />0<br />1<br />0<br />1<br />0<br />1<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:37</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bd88cc4f9d52',t:'MTY5NjY0NjAxNy40OTYwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Heaps, binary search trees, segment trees, hash tables, etc\", \"Dfs and similar\", \"Graphs\", \"Trees\"]"},"short_tags":{"kind":"string","value":"[\"data structures\", \"dfs and similar\", \"graphs\", \"trees\", \"*2100\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8860"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"21ba25574a0615e5dc71db6e32a512d8\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #200 Tutorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #200 Tutorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='21ba25574a0615e5dc71db6e32a512d8'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8860\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/gen\">gen</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gen\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gen\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gen\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gen\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gen\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gen\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gen\" style=\"text-decoration:none;color:black !important;\">gen's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8915\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8860\"> <p>Codeforces Round #200 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a>,\r\n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h4><a href=\"/contest/344/problem/A\" title=\"Codeforces Round 200 (Div. 2)\">344A - Magnets</a></h4><p>By the definition each block consists of a number of consequent and equally oriented dominoes. That means that in places where adjacent dominoes are not oriented equally, one block ends and another block starts. So, if there are <span class=\"tex-span\"><i>x</i></span> such places, the answer is equal to <span class=\"tex-span\"><i>x</i> + 1</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> The problem was created a day before the contest and filled in the last part of a physically flavoured DivII complect. :]</p><h4><a href=\"/contest/344/problem/B\" title=\"Codeforces Round 200 (Div. 2)\">344B - Simple Molecules</a></h4><p>First solution. First, the sum <span class=\"tex-span\"><i>a</i> + <i>b</i> + <i>c</i></span> should be even, since each bond adds 2 to the sum. Now let <span class=\"tex-span\"><i>x</i></span>, <span class=\"tex-span\"><i>y</i></span>, <span class=\"tex-span\"><i>z</i></span> be the number of bonds between 1st and 2nd, 2nd and 3rd, 3rd and 1st atoms, accordingly. So we have to solve the system <span class=\"tex-span\"><i>x</i> + <i>z</i> = <i>a</i></span>, <span class=\"tex-span\"><i>y</i> + <i>x</i> = <i>b</i></span>, <span class=\"tex-span\"><i>z</i> + <i>y</i> = <i>c</i></span>. Now observe that the solution to the system is the length of the tangents on the triangle with sides of length <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span> to its inscribed circle, and are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/2cee22ffa44dda3ce1b315e8cceef38c6288cf2c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1aed1c363b13d01e1b412b9cd3d5e34d19eb9c96.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/30fbfc651674588cadbee1fedd1e4b0d08d1ad4e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. If the problem asked only the possibility of building such a molecule, we could just check if there exists (possibly degenerate) triangle with sides <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span>.</p><p><img alt=\" \" src=\"/predownloaded/e3/d3/e3d3c930f4f93ca68c1e61630a2771472ecbd60a.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Second solution. Bruteforce all <span class=\"tex-span\"><i>x</i></span> values. For a fixed <span class=\"tex-span\"><i>x</i></span> values of <span class=\"tex-span\"><i>y</i></span> and <span class=\"tex-span\"><i>z</i></span> are defined uniquely: <span class=\"tex-span\"><i>y</i> = <i>b</i> - <i>x</i></span>, <span class=\"tex-span\"><i>z</i> = <i>a</i> - <i>x</i></span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(1) / <i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> Can you solve the problem for any vertex number <span class=\"tex-span\"><i>n</i></span>? When and how can such a graph be built?</p><h4><a href=\"/contest/343/problem/A\" title=\"Codeforces Round 200 (Div. 1)\">343A - Rational Resistance</a></h4><p>If a fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> can be obtained with <span class=\"tex-span\"><i>k</i></span> resistors, then it is simple to calculate that we can obtain fractions <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b6913fd8136f518e8a7898a9b759b74c4d483101.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/daf9572f0aa7677d7961c329e6277818df63bd9f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> with <span class=\"tex-span\"><i>k</i> + 1</span> resistors. So adding one resistor means performing one operation backwards in Euclidean algorithm. That means that the answer is equal to the number of steps in standard Euclidean algorithm.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e847ae811adbd761fa24db4ba7a6827e0806d670.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Бонус:</strong> At first we thought about the major problem (any two elements can be joined), but had a moment of eureka and got that the given problem unexpectedly naturally can be reduced to GCD. By the way, the result tree — <a href=\"https://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree\">http://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree</a>.</p><h4><a href=\"/contest/343/problem/B\" title=\"Codeforces Round 200 (Div. 1)\">343B - Alternating Current</a></h4><p>Let us solve the following problem first: we are given a string of symbols A and B. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>A</i></span>, then at the <span class=\"tex-span\"><i>i</i></span>-th step the upper wire (see figure) is being put over the lower wire. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>B</i></span>, the lower wire is being put over the upper wire at <span class=\"tex-span\"><i>i</i></span>-th step. Observe that if some two symbols <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are adjacent, we can untangle this place, throw the symbols out and obtain the string of length two symbols less. So the wires can be untangled iff the number of A's and B's in the string is the same. The given problem can be reduced to the described in a following fashion: in each odd position we change – to B and + to A. In each even position we change — to A and + to B. The reduction is correct, since on each even position the order of — and + are always swapped, and in each odd position their order is the same as in the beginning.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> If you are interested by this problem, you can learn about the braid theory <a href=\"https://en.wikipedia.org/wiki/Braid_theory\">http://en.wikipedia.org/wiki/Braid_theory</a> :] Fun fact: a harder version of this problem was planned already for Round #142, but the error in solution idea was found, and the problem was left to lay for almost a year.</p><h4><a href=\"/contest/343/problem/C\" title=\"Codeforces Round 200 (Div. 1)\">343C - Read Time</a></h4><p>Let's search the answer <span class=\"tex-span\"><i>t</i></span> with the binary search. Fix some value of <span class=\"tex-span\"><i>t</i></span>. Look at the first head from the left <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> that can read track <span class=\"tex-span\"><i>p</i>[0]</span>. If <span class=\"tex-span\"><i>p</i>[0] > <i>h</i>[<i>i</i>]</span>, then <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> goes to the right <span class=\"tex-span\"><i>t</i></span> seconds and reads all tracks on its way. Otherwise if <span class=\"tex-span\"><i>p</i>[0] ≤ <i>h</i>[<i>i</i>]</span>, then the head has two choices:</p> <ol> <li>go to the right <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> seconds, then <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> to the left and <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> again to the left;</li> <li>go to the left <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> seconds, then <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> to the right and <span class=\"tex-span\"><i>t</i> - 2·(<i>h</i>[<i>i</i>] - <i>p</i>[0])</span> again to the right.</li> </ol><p>Obviously, for <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> it is more advantageous to visit the track positioned as much as possible to the right. So we choose by <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7edc4f5554e1d173945160b7deaca92e61d7a755.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Then we move the pointer onto the first unread track, and repeat the algorithm for <span class=\"tex-span\"><i>h</i>[<i>i</i> + 1]</span>, and so on with each head.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/3342f24e1fd6ab939313f6d6278245c95d89544f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a>.</p><p><strong>Bonus:</strong> The problem is completely real, if the disk has only a single head, if we know, what tracks should be read; then the optimal algorithm chooses between the two choices described above. I and <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a> were listening this on a lecture, and created the given problem out of boredom ;]</p><h4><a href=\"/contest/343/problem/D\" title=\"Codeforces Round 200 (Div. 1)\">343D - Water Tree</a></h4><p>Let's learn how to color a whole subtree. For that enumerate all vertices in post-order DFS. Then each subtree covers a single continious vertex number segment. For each vertex we store the bounds of such segment for a subtree with a root in this vertex. Then to color a subtree means to color a segment in a segment tree.</p><p>Then create a segment tree that has a following property: if a vertex <span class=\"tex-span\"><i>v</i></span> was emptied, and is still empty, then this vertex is colored in the segment tree. In the beginning "empty" all the vertices. That is, color all the vertices in the segment tree. With this tree we can efficiently process the queries:</p> <ol> <li><p>Fill a vertex <span class=\"tex-span\"><i>v</i></span>. Clean the interval for the subtree of <span class=\"tex-span\"><i>v</i></span>. If before that some vertex of a subtree was empty, color the parent of <span class=\"tex-span\"><i>v</i></span>.</p></li> <li><p>Empty a vertex <span class=\"tex-span\"><i>v</i></span>. Color the vertex <span class=\"tex-span\"><i>v</i></span> in the segment tree.</p></li> <li><p>Reply whether a vertex <span class=\"tex-span\"><i>v</i></span> is filled. If in the segment tree at least one vertex is colored, then there is such a descendant of <span class=\"tex-span\"><i>v</i></span> that is empty now, so the vertex <span class=\"tex-span\"><i>v</i></span> is not filled.</p></li> </ol><p><a class=\"rated-user user-blue\" href=\"/profile/Shtrix\" title=\"Expert Shtrix\">Shtrix</a> noted that essentially the same solution can be implemented with only a single set.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fcb5cb34164112e0db4b3ef4b921f55df7ffb005.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> Some participants could see the similarities with a problem Ball Machine from BOI 2013, but the solutions to the both problems are quite different.</p><h4><a href=\"/contest/343/problem/E\" title=\"Codeforces Round 200 (Div. 1)\">343E - Pumping Stations</a></h4><p>In this problem we are asked to find such graph vertex permutation that maximizes the sum of the maximum flows sent between each two consequtive vertices in the permutation.</p><p>The problem can be solved with <a href=\"https://en.wikipedia.org/wiki/Gomory%E2%80%93Hu_tree\">Gomory-Hu</a> tree data structure. For a given weighted graph the tree has the following properties:</p> <ol> <li>The vertex set of the tree and the graph is the same.</li> <li>The maximum flow between vertices <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> in the tree is equal to the maximum flow in the graph.</li> </ol><p>Surprisingly, such a tree exists for any weighted graph, and can be built in <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. It appears that the answer to the problem is equal to the sum of the edge weights in this tree.</p><p>We prove this statement by induction on the number of the tree vertices. Pick the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> with the smallest weight in the tree. Consider that in an optimal permutation more than one path between two adjacent verteces in the permutation passes through this edge. Erase all these paths, then each of the <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> subtrees holds a set of disjoint remaining paths from the permutation. For each set, join all the paths in one chain, obtaining two chains. These chains we join by a path <span class=\"tex-span\"><i>s</i></span> that goes trough the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>. Thus we have built a permutation that is not worse than the considered one. For a path <span class=\"tex-span\"><i>s</i></span> the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> is the smallest, so the flow along this path is equal to the weight of this edge. It follows from the induction that in subtrees <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> the answer is equal to the sum of edges. By adding the weight of edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>, we get the desired result.</p><p>From the last paragraph it is clear how to build such a permutation: take the smallest edge, obtain two chains from the vertex subtrees recursively, and add them together to form a one chain. Since there are not many vertices, we can do this part in <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-orange\" href=\"/profile/Gerald\" title=\"Master Gerald\">Gerald</a>.</p><p><strong>Bonus:</strong> Shortly before the contest we decided to make the constraints more loyal, so some solution that find Gomory-Hu tree by finding flow <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> times also passed. We hope that nobody is particularly saddened by this fact. (;</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/343\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/344\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-8915\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"8860\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=200\" class=\"tag notice\" style=\"text-decoration: none;\">200</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+64</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8860#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8860#comments\">\n 53\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8931\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (43)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145823\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bipinb1994\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/91315/avatar/b4e2d8ac5b2569a3.jpg'/> </a>\n <div><a href=\"/profile/bipinb1994\" title=\"Expert bipinb1994\" class=\"rated-user user-blue\">bipinb1994</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 07:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145823\" href=\"?#comment-145823\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145823\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-15\"\r\n data-commentUserId=\"91315\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145823\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hai this was my first round in Codeforces. But my code was not accepted and it says that it was wrong with the 3rd test case. What i did was put a loop from 0 to n-1 and i checked ch[i][!=ch[i+1][0] then count++; else continue where 'ch' is the character array(2-D) whose size was Nx3 ...Is this algorithm completely wrong. As i said this was the first round here i did not understand what is wrong with this. If possible please do tell me what is wrong with this algorithm..:(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145823 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145823 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145823\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145863\" commentParentId=\"145823\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 14:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145863\" href=\"?#comment-145863\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145823\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145863\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145863\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please look at link <a href=\"//codeforces.com/contest/344/submission/4461494\">http://codeforces.com/contest/344/submission/4461494</a>. </p><p>The log says</p><p>Time: 0 ms, memory: 0 KB Verdict: WRONG_ANSWER Input 1 10 Output 0 Answer 1 Checker comment wrong answer 1st numbers differ — expected: '1', found: '0'</p><p>I believe this should be self explanatory. </p><p>Also it would help playing around with the system before trying to enter a rated match.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145863 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145863 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145863\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146026\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ka16\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ka16\" title=\"Pupil ka16\" class=\"rated-user user-green\">ka16</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 06:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146026\" href=\"?#comment-146026\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146026\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"12131\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146026\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody please clarify the two choices of head(s) in the solution of 343C-Read Time problem above? I couldn't understand it completely. Thank in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146026 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146026 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146026\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146037\" commentParentId=\"146026\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hriss95\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27396/avatar/d6cec8eac7bdbde3.jpg'/> </a>\n <div><a href=\"/profile/hriss95\" title=\"Expert hriss95\" class=\"rated-user user-blue\">hriss95</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 13:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146037\" href=\"?#comment-146037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146026\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146037\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"27396\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have to choose one of the two types moving: first to the right or first to the left. You have to use the one which covers more points to the right. Note that both types of moving cover the left point and that's why you have to take as much as points as you can to the right.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146037\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sorin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/sorin\" title=\"Expert sorin\" class=\"rated-user user-blue\">sorin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 12:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146034\" href=\"?#comment-146034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"124904\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody give me a hint for the bonus at Div2 — B? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146034\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146064\" commentParentId=\"146034\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 21:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146064\" href=\"?#comment-146064\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146034\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146064\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146064\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Think greedy ;]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146064 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146064 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146064\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"152157\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ghooo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2010/avatar/659a8aca8b12506a.jpg'/> </a>\n <div><a href=\"/profile/ghooo\" title=\"Master ghooo\" class=\"rated-user user-orange\">ghooo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/26/2013 08:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-152157\" href=\"?#comment-152157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"152157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2010\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-152157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>will the connections between the atoms be circular? like 1 <-> 2 <-> 3 <-> 4 <-> 5 ... n <-> 1 (again) ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-152157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-152157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-152157\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"521750\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/n0tred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1177564/avatar/a46e0281e87dd6c9.jpg'/> </a>\n <div><a href=\"/profile/n0tred\" title=\"Candidate Master n0tred\" class=\"rated-user user-violet\">n0tred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/25/2019 14:29\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-521750\" href=\"?#comment-521750\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"521750\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1177564\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-521750\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you give a better hint? (Maybe through a spoiler, I suppose)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-521750 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-521750 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-521750\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"523308\" commentParentId=\"521750\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/29/2019 09:36\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-523308\" href=\"?#comment-523308\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-521750\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"523308\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-523308\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the algorithm that continuously connects the vertex with the smallest degree with the vertex with the largest degree works (here by degree I mean the unconnected edges), and builds a connected graph. I think this can be proved by induction.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-523308 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-523308 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-523308\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146129\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 11:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146129\" href=\"?#comment-146129\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146129\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146129\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think there is an issue with Problem 343A — Rational Resistance. Here according to the editorial the answer to the ratio 6/5 would be 6(I have verified this with an accepted solution). But this ratio can be achieved with a resistance of 2 and 3 in parallel, which makes the number of resistors required equal to 5 which would imply the editorial and the system tests to be wrong.</p><p>Am I missing something here?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146129 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146129 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146129\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146259\" commentParentId=\"146129\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146259\" href=\"?#comment-146259\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146129\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146259\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146259\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think it's because the definition of <strong>one element</strong> only let you add <strong>one</strong> new unit resistor to another element</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146259 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146259 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146259\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146256\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146256\" href=\"?#comment-146256\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146256\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146256\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for the nice problems!</p><p>I just have a little question on 343C — Read Time. I use the same algorithm and get AC, but my algorithm is running at O(n log^2 n)... as for the step: "Then we move the pointer onto the first unread track" I use another binary search...</p><p>how can I implement the same algorithm with O(n log n) as said in editorial? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146256 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146256 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146256\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146269\" commentParentId=\"146256\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146269\" href=\"?#comment-146269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146256\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146269\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We hold two pointers: the first points at the first unread track from the left, and the second points at the first unused head so far. So we take this head and read with its help the maximum number of yet unread tracks (note that they are consequent and begin at the first pointer) according to the best of the two choices described in tutorial. Then we move the first pointer to the first yet unread track, and increment the second by one. Thus each pointer moves <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> times in this iteration of the binary search. Take also in consideration that some heads can be not used at all.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154161\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/s2k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146708/avatar/ec43946f377e5c64.jpg'/> </a>\n <div><a href=\"/profile/s2k\" title=\"Newbie s2k\" class=\"rated-user user-gray\">s2k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154161\" href=\"?#comment-154161\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154161\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146708\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154161\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi. I was just trying to solve problem A of division 2, but was unsuccessful after hours of effort. I eventually lost patience and decided to see the codes of others. I did understand what was going in the code, but couldn't figure out why this method was chosen in the first place. Can someone please help me understand the solution?</p><p>P.S. I'm a newbie with almost no prior knowledge about number theory. :$</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154161 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154161 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154161\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154163\" commentParentId=\"154161\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154163\" href=\"?#comment-154163\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-154161\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154163\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154163\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The number of islands is always one more than the number of splits between two neighboring dominoes. One can easily convince himself by looking at an image in the description.</p><p>There are 4 possibilities of neighboring dominoes:</p> <ul> <li>01 and 01: these attract, so they don't form a split and we don't care about them</li> <li>10 and 10: these attract, so they don't form a split and we don't care about them</li> <li>01 and 10: these don't attract, so they form a split</li> <li>10 and 01: these don't attract, so they form a split</li> </ul><p>So, we can deduce that we're only interested in neighboring dominoes that are different. This means we can just count the number of indexes i (1 <= i < N) such that s[i] != s[i+1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154163 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154163 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154163\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176652\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/S.Ged\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67184/avatar/a38f51555a40b56a.jpg'/> </a>\n <div><a href=\"/profile/S.Ged\" title=\"Candidate Master S.Ged\" class=\"rated-user user-violet\">S.Ged</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 04:10\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176652\" href=\"?#comment-176652\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"176652\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"176652\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"67184\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176652\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm confused by the first sentence of 343A — Rational Resistance tutorial</p><p>How can we obtain a/(a+b) with k+1 resistors if obatined a/b wiht k resistors ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176652 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176652 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176652\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176656\" commentParentId=\"176652\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/afrizal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/103639/avatar/206f6cf479b00060.jpg'/> </a>\n <div><a href=\"/profile/afrizal\" title=\"Expert afrizal\" class=\"rated-user user-blue\">afrizal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 07:05\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176656\" href=\"?#comment-176656\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176652\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"176656\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"103639\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176656\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Remember a/a is 1. If we have a/b resistance, put one more resistor parallel will give <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c1a16b55f7f10840909e0e5863ae3ce22e36c85b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176656 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176656 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176656\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"189636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/namikaze\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/227989/avatar/51e67e9e139a65f2.jpg'/> </a>\n <div><a href=\"/profile/namikaze\" title=\"Unrated, namikaze\" class=\"rated-user user-black\">namikaze</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/28/2014 15:45\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-189636\" href=\"?#comment-189636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"189636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"227989\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-189636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><code>adding one resistor means performing one operation backwards in Euclidean algorithm</code></p><p>Can someone explain this ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-189636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-189636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-189636\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"277029\" commentParentId=\"189636\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TomBombadil\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/106415/avatar/ed9d8ef375273241.jpg'/> </a>\n <div><a href=\"/profile/TomBombadil\" title=\"Specialist TomBombadil\" class=\"rated-user user-cyan\">TomBombadil</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2016 17:50\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-277029\" href=\"?#comment-277029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-189636\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"277029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"106415\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-277029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-orange\" href=\"/profile/gen\" title=\"Master gen\">gen</a> ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-277029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-277029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-277029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"351231\" commentParentId=\"277029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/R.A.X\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/122476/avatar/686763c746ac6e7b.jpg'/> </a>\n <div><a href=\"/profile/R.A.X\" title=\"Specialist R.A.X\" class=\"rated-user user-cyan\">R.A.X</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/27/2017 15:37\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-351231\" href=\"?#comment-351231\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-277029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"351231\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"351231\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"122476\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-351231\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Suppose you have resistance of(17/3), it could be formed by adding 1 + (14/3). If you have resistance of (3/17), it could be obtained by combining resistance of 1 and 3/14 in parallel.</p><p>In terms of variable, a/b could be obtained by 1 + resistors required to create ( a-b)/b resistance, assuming a>b. and a/b if b>a, could be obtained by 1 + resistors required to create ( a/(b-a) ).</p><p>Assuming a>b so resistorRequired(a,b) = 1 + resistorRequired(a-b,b).</p> <pre>resistorReqiored(a-b,b) = 1 + resistorRequired(a-2b,b)</pre><p>............</p> <pre>resistorRequired(a-(q-1)*b ,b) = 1 + resistorRequired(a-q*b,b)</pre><p>let say r = a-q*b == a%b now at this point, one resistance needs to be connected in parallel to the b/r resistance.</p><p>so again problem becomes calculating the requiredResistance(b,r) similar to above problem,</p><p>which is similar to the gcd problem.</p><p>Hope that helps.</p><p>Why it's like gcd(a,b) = gcd(a-b,b) =gcd(a-2b,b) .... </p><p>In case of gcd(a,b) = gcd(a-b,b)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-351231 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-351231 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-351231\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"393063\" commentParentId=\"351231\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ShafinKhadem\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/508696/avatar/1b5c8ae9cf51dc77.jpg'/> </a>\n <div><a href=\"/profile/ShafinKhadem\" title=\"Master ShafinKhadem\" class=\"rated-user user-orange\">ShafinKhadem</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/01/2017 09:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-393063\" href=\"?#comment-393063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-351231\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"393063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"508696\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-393063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for the nice explanation. Now the use of euclidian algorithm to solve this problem makes sense to me.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-393063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-393063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-393063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"220282\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CloverAsta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207753/avatar/45b71a38344fa830.jpg'/> </a>\n <div><a href=\"/profile/CloverAsta\" title=\"Expert CloverAsta\" class=\"rated-user user-blue\">CloverAsta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/01/2015 14:33\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-220282\" href=\"?#comment-220282\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"220282\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207753\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-220282\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain to me the solution for Problem C div2 I understand the transition from <code>k</code> to <code>k + 1</code> but the part about Euclidean algorithm is beyond me</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-220282 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-220282 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-220282\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"232136\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anajin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221428/avatar/b8f5979933e2ce3d.jpg'/> </a>\n <div><a href=\"/profile/anajin\" title=\"Expert anajin\" class=\"rated-user user-blue\">anajin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/03/2015 14:15\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-232136\" href=\"?#comment-232136\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"232136\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-232136\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>water tree can be solved by heavy-light decomposition...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-232136 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-232136 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-232136\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"454886\" commentParentId=\"232136\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cai_lw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/325977/avatar/202b61935928944.jpg'/> </a>\n <div><a href=\"/profile/cai_lw\" title=\"International Master cai_lw\" class=\"rated-user user-orange\">cai_lw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/30/2018 20:04\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-454886\" href=\"?#comment-454886\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-232136\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"454886\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"454886\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"325977\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-454886\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, this is almost the most standard problem for HLD. But their solution is cleverer and has lower time complexity. HLD is a little bit overkill for such simple operations.</p><p>Nevertheless, HLD can pass the test. My HLD solution passed in 900ms.</p><p>Also HLD was a relatively unknown algorithm to the CP community 5 years ago.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-454886 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-454886 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-454886\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"634570\" commentParentId=\"454886\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Suri429\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/776807/avatar/90399ec92a81320a.jpg'/> </a>\n <div><a href=\"/profile/Suri429\" title=\"Master Suri429\" class=\"rated-user user-orange\">Suri429</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2020 08:55\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-634570\" href=\"?#comment-634570\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-454886\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"634570\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"776807\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-634570\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain how to approach this with HLD? I am new to HLD, and not able to get any clue here. </p><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-634570 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-634570 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-634570\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"312598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/29/2016 12:31\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-312598\" href=\"?#comment-312598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"312598\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"312598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-312598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder why I did wrong in the implementation of lazy propagation for Div1D, could anyone kindly lend some help? </p><p><a href=\"//codeforces.com/contest/343/submission/20226349\">http://codeforces.com/contest/343/submission/20226349</a></p><p>Thanks in advance. =)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-312598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-312598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-312598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"357445\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anshulgarg19\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/anshulgarg19\" title=\"Pupil anshulgarg19\" class=\"rated-user user-green\">anshulgarg19</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/02/2017 20:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-357445\" href=\"?#comment-357445\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"357445\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"244328\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-357445\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Accepted solution for the problem 343A Rational Resistance would give 6 as the output for input a = 10 and b = 7 i.e.10/7. But, if we have 5 ohm and 2 ohm resistors in parallel, then we have the same resistance value 10/7. So minimum value should be 2 resistors for this case. Kindly explain if i am wrong in understanding the problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-357445 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-357445 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-357445\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360009\" commentParentId=\"357445\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/snehil10\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/351506/avatar/522f61633a219a3b.jpg'/> </a>\n <div><a href=\"/profile/snehil10\" title=\"Expert snehil10\" class=\"rated-user user-blue\">snehil10</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/14/2017 10:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360009\" href=\"?#comment-360009\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-357445\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"360009\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"351506\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360009\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have only 1-ohm resistors in the beginning. Thus it requires 5 1-ohm resistors to make a 5-ohm resistor, and 2 1-ohm resistors to make a 2-ohm resistor. So according to you answer is 7 and not 2.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360009 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360009 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360009\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371475\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rush_123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/rush_123\" title=\"Expert rush_123\" class=\"rated-user user-blue\">rush_123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/03/2017 17:42\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371475\" href=\"?#comment-371475\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"371475\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"439840\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371475\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 343D — Water Tree query 1 and 2 can be solved using a dfs to find in time and out time for every node and then using segment tree But what about 3rd query how to solve it?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371475 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371475 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371475\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"422269\" commentParentId=\"371475\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stringray\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/575608/avatar/2902babcf56868a2.jpg'/> </a>\n <div><a href=\"/profile/stringray\" title=\"Expert stringray\" class=\"rated-user user-blue\">stringray</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/28/2018 16:13\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-422269\" href=\"?#comment-422269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371475\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"422269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"575608\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-422269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yeah same question .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-422269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-422269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-422269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"437012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ragnarok_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ragnarok_\" title=\"Newbie ragnarok_\" class=\"rated-user user-gray\">ragnarok_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2018 08:59\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-437012\" href=\"?#comment-437012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"437012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"673189\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-437012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Q.343A can anybody explain me why min resistor for 199/200 is 200.....it can be also constructed using 101 resistors(1/2+1/4+1/5+1/40+1/50)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-437012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-437012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-437012\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"573631\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SLIMSHADYNICK\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/598862/avatar/7629f1b29f0fe807.jpg'/> </a>\n <div><a href=\"/profile/SLIMSHADYNICK\" title=\"Candidate Master SLIMSHADYNICK\" class=\"rated-user user-violet\">SLIMSHADYNICK</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2020 21:03\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-573631\" href=\"?#comment-573631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"573631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"598862\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-573631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>correct!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-573631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-573631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-573631\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587715\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pied-piper\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/754580/avatar/a6fb81d49bb96665.jpg'/> </a>\n <div><a href=\"/profile/pied-piper\" title=\"Expert pied-piper\" class=\"rated-user user-blue\">pied-piper</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/11/2020 16:14\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587715\" href=\"?#comment-587715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"587715\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"587715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"754580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It is because they are separate elements and hence they cannot be added together. Only an element and a 1 unit resistance can be added in series(or parallel)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587715\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"791297\" commentParentId=\"587715\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/15/2021 17:25\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-791297\" href=\"?#comment-791297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587715\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"791297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-791297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-791297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-791297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-791297\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"598229\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayank_ag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/644568/avatar/c1136e364e721d18.jpg'/> </a>\n <div><a href=\"/profile/mayank_ag\" title=\"Master mayank_ag\" class=\"rated-user user-orange\">mayank_ag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/05/2020 20:53\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-598229\" href=\"?#comment-598229\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"598229\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"644568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-598229\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>An alternate approach for solving D: Use of lazy segment tree over HLD & Euler path. For every filling, fill Euler path with current query number, and for emptying, fill HLD path from the root with query number. For queries, check which of the seg tree has high query number.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-598229 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-598229 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-598229\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"600816\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Asterix_11\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Asterix_11\" title=\"Pupil Asterix_11\" class=\"rated-user user-green\">Asterix_11</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/11/2020 00:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-600816\" href=\"?#comment-600816\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"600816\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1472760\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-600816\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem 344A</p> <pre><code>#include <iostream>\nusing namespace std;\nint main()\n{\n int a, i, b[100], ans;\n scanf("%d", &a);\n for(i = 0; i < a; ++i){\n scanf("%d", &b[i]);\n }\n ans = 1;\n for(i = 0; i < (a-1); ++i){\n if(b[i] != b[i + 1]){\n ++ans;}\n }\n printf("%d", ans);\n return 0;\n}\n</code></pre><p>This is my code, but I don't know how to improve it, so that the time limit won't be a problem anymore. Any help?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-600816 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-600816 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-600816\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752098\" commentParentId=\"600816\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 09:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752098\" href=\"?#comment-752098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-600816\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can make two variable for prev and current value and if they are not equal you can increment it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752098\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752075\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:25\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752075\" href=\"?#comment-752075\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752075\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752075\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Problem C, if more than one of the elements can be in parallel than for ratio 199 and 200 the answer given is 200. But we may solve this in 74. like 1/2+1/4+1/8+1/10+1/50.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752075 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752075 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752075\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752089\" commentParentId=\"752075\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752089\" href=\"?#comment-752089\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-752075\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752089\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752089\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Okay it would be like either + denominator to the numerator or + numerator to the denominator.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752089 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752089 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752089\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"946539\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mohsina_Shaikh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1396580/avatar/6f21616a2d8d578.jpg'/> </a>\n <div><a href=\"/profile/Mohsina_Shaikh\" title=\"Newbie Mohsina_Shaikh\" class=\"rated-user user-gray\">Mohsina_Shaikh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/24/2022 06:47\">13 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-946539\" href=\"?#comment-946539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"946539\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"946539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1396580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-946539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a> or <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a> or can anyone please explain <code>Alternating Current</code> Solution.Tried so hard but not able to understand it. A</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-946539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-946539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-946539\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"959164\" commentParentId=\"946539\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rishijoshi483\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2453886/avatar/1ecf48b346fe39d0.jpg'/> </a>\n <div><a href=\"/profile/rishijoshi483\" title=\"Expert rishijoshi483\" class=\"rated-user user-blue\">rishijoshi483</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/03/2022 09:44\">12 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-959164\" href=\"?#comment-959164\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-946539\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"959164\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2453886\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-959164\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try it using stack</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-959164 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-959164 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-959164\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"966651\" commentParentId=\"959164\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Yohajji\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2854745/avatar/b31d6e4c63852741.jpg'/> </a>\n <div><a href=\"/profile/Yohajji\" title=\"Newbie Yohajji\" class=\"rated-user user-gray\">Yohajji</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2022 13:35\">11 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-966651\" href=\"?#comment-966651\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-959164\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"966651\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2854745\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-966651\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>using the stack was a brilliant aproach, thank you </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-966651 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-966651 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-966651\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1039007\" commentParentId=\"966651\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AbdelrahmanMahallawy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3189297/avatar/6b2a1658ad37caa0.jpg'/> </a>\n <div><a href=\"/profile/AbdelrahmanMahallawy\" title=\"Newbie AbdelrahmanMahallawy\" class=\"rated-user user-gray\">AbdelrahmanMahallawy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/20/2023 03:36\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1039007\" href=\"?#comment-1039007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-966651\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1039007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3189297\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1039007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>anytime </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1039007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1039007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1039007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8931\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8931 = true;\r\nvar lastPreviewContent8931 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8931] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8931] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:23</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128748fcb8816ab',t:'MTY5NjcwNTk0My4yOTkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1741,"cells":{"problem_id":{"kind":"string","value":"343E"},"contest":{"kind":"string","value":"343"},"problem":{"kind":"string","value":"E"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"E. Pumping Stations"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Pumping Stations</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike has applied for a job. His task is to manage a system of water pumping stations.</p><p>The system consists of <span class=\"tex-span\"><i>n</i></span> pumping stations, which are numbered by integers from 1 to <span class=\"tex-span\"><i>n</i></span>. Some pairs of stations are connected by bidirectional pipes through which water can flow in either direction (but only in one at a time). For each pipe you know its bandwidth — the maximum number of liters of water that can flow through it in one hour. Each pumping station can pump incoming water from some stations to other stations through the pipes, provided that in one hour the total influx of water to the station is equal to the total outflux of water from the station.</p><p>It is Mike's responsibility to pump water between stations. From station <span class=\"tex-span\"><i>a</i></span> to station <span class=\"tex-span\"><i>b</i></span> through the pipes (possibly through other stations) within one hour one can transmit a certain number of liters of water according to the rules described above. During this time, water from other stations can not flow into station <span class=\"tex-span\"><i>a</i></span>, and can not flow out of the station <span class=\"tex-span\"><i>b</i></span>. However, any amount of water can flow out of station <span class=\"tex-span\"><i>a</i></span> or in station <span class=\"tex-span\"><i>b</i></span>. If a total of <span class=\"tex-span\"><i>x</i></span> litres of water flows out of the station <span class=\"tex-span\"><i>a</i></span> in an hour, then Mike gets <span class=\"tex-span\"><i>x</i></span> bollars more to his salary.</p><p>To get paid, Mike needs to work for <span class=\"tex-span\"><i>n</i> - 1</span> days, according to the contract. On the first day he selects two stations <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">2</sub></span>, and within one hour he pumps a certain amount of water from <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">1</sub></span> to <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">2</sub></span>. Next, on the <span class=\"tex-span\"><i>i</i></span>-th day Mike chooses a station <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span> that has been never selected before, and pumps a certain amount of water out of the station <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> to station <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span> for one hour. The quantity of water he pumps on the <span class=\"tex-span\"><i>i</i></span>-th day <span class=\"tex-font-style-bf\">does not depend</span> on the amount of water pumped on the <span class=\"tex-span\">(<i>i</i> - 1)</span>-th day.</p><p>Mike needs to earn as much bollars as he can for his projects. Help Mike find such a permutation of station numbers <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>n</i></sub></span> so Mike will be able to earn the highest possible salary.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains two space-separated integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 200</span>, <span class=\"tex-span\">1 ≤ <i>m</i> ≤ 1000</span>) — the number of stations and pipes in the system, accordingly. The <span class=\"tex-span\"><i>i</i></span>-th of the next <span class=\"tex-span\"><i>m</i></span> lines contains three space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\">1 ≤ <i>c</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100</span>) — the numbers of stations connected by the <span class=\"tex-span\"><i>i</i></span>-th pipe and the pipe's bandwidth, accordingly. It is guaranteed that any two stations are connected by at most one pipe and that there is a pipe path between any two stations.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>On the first line print a single integer — the maximum salary Mike can earn.</p><p>On the second line print a space-separated permutation of <span class=\"tex-span\"><i>n</i></span> numbers from 1 to <span class=\"tex-span\"><i>n</i></span> — the numbers of stations in the sequence <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>n</i></sub></span>. If there are multiple answers, print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>6 11<br/>1 2 10<br/>1 6 8<br/>2 3 4<br/>2 5 2<br/>2 6 3<br/>3 4 5<br/>3 5 4<br/>3 6 2<br/>4 5 7<br/>4 6 2<br/>5 6 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>77<br/>6 2 1 5 3 4 <br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"82527622b2080e1b390dfaae9b34ab8f\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"c35c56cdf057f72810b979434cacadcbf2ca863c\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='82527622b2080e1b390dfaae9b34ab8f'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F343%2Fproblem%2FE%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='82527622b2080e1b390dfaae9b34ab8f'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/343\">Codeforces Round 200 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='82527622b2080e1b390dfaae9b34ab8f'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/343/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Brute force\">\r\n brute force\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dfs and similar\">\r\n dfs and similar\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Divide and Conquer\">\r\n divide and conquer\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Graph network flows\">\r\n flows\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Graphs\">\r\n graphs\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Trees\">\r\n trees\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2900\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='82527622b2080e1b390dfaae9b34ab8f'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3471\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='82527622b2080e1b390dfaae9b34ab8f'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3471\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8851\" title=\"Codeforces Round #200\" target=\"_blank\">Codeforces Round #200</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1852:1853\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8860\" title=\"Codeforces Round #200 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1848:1849\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/343\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/343/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/343/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/343/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/343/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/343/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/343/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/343/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_ba77ba2e6f2eb810239369abfb42775bafabbb30\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Pumping Stations</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike has applied for a job. His task is to manage a system of water pumping stations.</p><p>The system consists of <span class=\"tex-span\"><i>n</i></span> pumping stations, which are numbered by integers from 1 to <span class=\"tex-span\"><i>n</i></span>. Some pairs of stations are connected by bidirectional pipes through which water can flow in either direction (but only in one at a time). For each pipe you know its bandwidth — the maximum number of liters of water that can flow through it in one hour. Each pumping station can pump incoming water from some stations to other stations through the pipes, provided that in one hour the total influx of water to the station is equal to the total outflux of water from the station.</p><p>It is Mike's responsibility to pump water between stations. From station <span class=\"tex-span\"><i>a</i></span> to station <span class=\"tex-span\"><i>b</i></span> through the pipes (possibly through other stations) within one hour one can transmit a certain number of liters of water according to the rules described above. During this time, water from other stations can not flow into station <span class=\"tex-span\"><i>a</i></span>, and can not flow out of the station <span class=\"tex-span\"><i>b</i></span>. However, any amount of water can flow out of station <span class=\"tex-span\"><i>a</i></span> or in station <span class=\"tex-span\"><i>b</i></span>. If a total of <span class=\"tex-span\"><i>x</i></span> litres of water flows out of the station <span class=\"tex-span\"><i>a</i></span> in an hour, then Mike gets <span class=\"tex-span\"><i>x</i></span> bollars more to his salary.</p><p>To get paid, Mike needs to work for <span class=\"tex-span\"><i>n</i> - 1</span> days, according to the contract. On the first day he selects two stations <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">2</sub></span>, and within one hour he pumps a certain amount of water from <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">1</sub></span> to <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">2</sub></span>. Next, on the <span class=\"tex-span\"><i>i</i></span>-th day Mike chooses a station <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span> that has been never selected before, and pumps a certain amount of water out of the station <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> to station <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span> for one hour. The quantity of water he pumps on the <span class=\"tex-span\"><i>i</i></span>-th day <span class=\"tex-font-style-bf\">does not depend</span> on the amount of water pumped on the <span class=\"tex-span\">(<i>i</i> - 1)</span>-th day.</p><p>Mike needs to earn as much bollars as he can for his projects. Help Mike find such a permutation of station numbers <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>n</i></sub></span> so Mike will be able to earn the highest possible salary.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains two space-separated integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 200</span>, <span class=\"tex-span\">1 ≤ <i>m</i> ≤ 1000</span>) — the number of stations and pipes in the system, accordingly. The <span class=\"tex-span\"><i>i</i></span>-th of the next <span class=\"tex-span\"><i>m</i></span> lines contains three space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\">1 ≤ <i>c</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100</span>) — the numbers of stations connected by the <span class=\"tex-span\"><i>i</i></span>-th pipe and the pipe's bandwidth, accordingly. It is guaranteed that any two stations are connected by at most one pipe and that there is a pipe path between any two stations.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>On the first line print a single integer — the maximum salary Mike can earn.</p><p>On the second line print a space-separated permutation of <span class=\"tex-span\"><i>n</i></span> numbers from 1 to <span class=\"tex-span\"><i>n</i></span> — the numbers of stations in the sequence <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>n</i></sub></span>. If there are multiple answers, print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>6 11<br />1 2 10<br />1 6 8<br />2 3 4<br />2 5 2<br />2 6 3<br />3 4 5<br />3 5 4<br />3 6 2<br />4 5 7<br />4 6 2<br />5 6 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>77<br />6 2 1 5 3 4 <br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:38</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bd90e9f316e8',t:'MTY5NjY0NjAxOC43ODUwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Brute force\", \"Dfs and similar\", \"Divide and Conquer\", \"Graph network flows\", \"Graphs\", \"Greedy algorithms\", \"Trees\"]"},"short_tags":{"kind":"string","value":"[\"brute force\", \"dfs and similar\", \"divide and conquer\", \"flows\", \"graphs\", \"greedy\", \"trees\", \"*2900\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8860"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"21ba25574a0615e5dc71db6e32a512d8\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #200 Tutorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #200 Tutorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='21ba25574a0615e5dc71db6e32a512d8'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8860\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/gen\">gen</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gen\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gen\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gen\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gen\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gen\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gen\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gen\" style=\"text-decoration:none;color:black !important;\">gen's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8915\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8860\"> <p>Codeforces Round #200 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a>,\r\n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h4><a href=\"/contest/344/problem/A\" title=\"Codeforces Round 200 (Div. 2)\">344A - Magnets</a></h4><p>By the definition each block consists of a number of consequent and equally oriented dominoes. That means that in places where adjacent dominoes are not oriented equally, one block ends and another block starts. So, if there are <span class=\"tex-span\"><i>x</i></span> such places, the answer is equal to <span class=\"tex-span\"><i>x</i> + 1</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> The problem was created a day before the contest and filled in the last part of a physically flavoured DivII complect. :]</p><h4><a href=\"/contest/344/problem/B\" title=\"Codeforces Round 200 (Div. 2)\">344B - Simple Molecules</a></h4><p>First solution. First, the sum <span class=\"tex-span\"><i>a</i> + <i>b</i> + <i>c</i></span> should be even, since each bond adds 2 to the sum. Now let <span class=\"tex-span\"><i>x</i></span>, <span class=\"tex-span\"><i>y</i></span>, <span class=\"tex-span\"><i>z</i></span> be the number of bonds between 1st and 2nd, 2nd and 3rd, 3rd and 1st atoms, accordingly. So we have to solve the system <span class=\"tex-span\"><i>x</i> + <i>z</i> = <i>a</i></span>, <span class=\"tex-span\"><i>y</i> + <i>x</i> = <i>b</i></span>, <span class=\"tex-span\"><i>z</i> + <i>y</i> = <i>c</i></span>. Now observe that the solution to the system is the length of the tangents on the triangle with sides of length <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span> to its inscribed circle, and are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/2cee22ffa44dda3ce1b315e8cceef38c6288cf2c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1aed1c363b13d01e1b412b9cd3d5e34d19eb9c96.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/30fbfc651674588cadbee1fedd1e4b0d08d1ad4e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. If the problem asked only the possibility of building such a molecule, we could just check if there exists (possibly degenerate) triangle with sides <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span>.</p><p><img alt=\" \" src=\"/predownloaded/e3/d3/e3d3c930f4f93ca68c1e61630a2771472ecbd60a.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Second solution. Bruteforce all <span class=\"tex-span\"><i>x</i></span> values. For a fixed <span class=\"tex-span\"><i>x</i></span> values of <span class=\"tex-span\"><i>y</i></span> and <span class=\"tex-span\"><i>z</i></span> are defined uniquely: <span class=\"tex-span\"><i>y</i> = <i>b</i> - <i>x</i></span>, <span class=\"tex-span\"><i>z</i> = <i>a</i> - <i>x</i></span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(1) / <i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> Can you solve the problem for any vertex number <span class=\"tex-span\"><i>n</i></span>? When and how can such a graph be built?</p><h4><a href=\"/contest/343/problem/A\" title=\"Codeforces Round 200 (Div. 1)\">343A - Rational Resistance</a></h4><p>If a fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> can be obtained with <span class=\"tex-span\"><i>k</i></span> resistors, then it is simple to calculate that we can obtain fractions <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b6913fd8136f518e8a7898a9b759b74c4d483101.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/daf9572f0aa7677d7961c329e6277818df63bd9f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> with <span class=\"tex-span\"><i>k</i> + 1</span> resistors. So adding one resistor means performing one operation backwards in Euclidean algorithm. That means that the answer is equal to the number of steps in standard Euclidean algorithm.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e847ae811adbd761fa24db4ba7a6827e0806d670.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Бонус:</strong> At first we thought about the major problem (any two elements can be joined), but had a moment of eureka and got that the given problem unexpectedly naturally can be reduced to GCD. By the way, the result tree — <a href=\"https://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree\">http://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree</a>.</p><h4><a href=\"/contest/343/problem/B\" title=\"Codeforces Round 200 (Div. 1)\">343B - Alternating Current</a></h4><p>Let us solve the following problem first: we are given a string of symbols A and B. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>A</i></span>, then at the <span class=\"tex-span\"><i>i</i></span>-th step the upper wire (see figure) is being put over the lower wire. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>B</i></span>, the lower wire is being put over the upper wire at <span class=\"tex-span\"><i>i</i></span>-th step. Observe that if some two symbols <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are adjacent, we can untangle this place, throw the symbols out and obtain the string of length two symbols less. So the wires can be untangled iff the number of A's and B's in the string is the same. The given problem can be reduced to the described in a following fashion: in each odd position we change – to B and + to A. In each even position we change — to A and + to B. The reduction is correct, since on each even position the order of — and + are always swapped, and in each odd position their order is the same as in the beginning.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> If you are interested by this problem, you can learn about the braid theory <a href=\"https://en.wikipedia.org/wiki/Braid_theory\">http://en.wikipedia.org/wiki/Braid_theory</a> :] Fun fact: a harder version of this problem was planned already for Round #142, but the error in solution idea was found, and the problem was left to lay for almost a year.</p><h4><a href=\"/contest/343/problem/C\" title=\"Codeforces Round 200 (Div. 1)\">343C - Read Time</a></h4><p>Let's search the answer <span class=\"tex-span\"><i>t</i></span> with the binary search. Fix some value of <span class=\"tex-span\"><i>t</i></span>. Look at the first head from the left <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> that can read track <span class=\"tex-span\"><i>p</i>[0]</span>. If <span class=\"tex-span\"><i>p</i>[0] > <i>h</i>[<i>i</i>]</span>, then <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> goes to the right <span class=\"tex-span\"><i>t</i></span> seconds and reads all tracks on its way. Otherwise if <span class=\"tex-span\"><i>p</i>[0] ≤ <i>h</i>[<i>i</i>]</span>, then the head has two choices:</p> <ol> <li>go to the right <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> seconds, then <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> to the left and <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> again to the left;</li> <li>go to the left <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> seconds, then <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> to the right and <span class=\"tex-span\"><i>t</i> - 2·(<i>h</i>[<i>i</i>] - <i>p</i>[0])</span> again to the right.</li> </ol><p>Obviously, for <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> it is more advantageous to visit the track positioned as much as possible to the right. So we choose by <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7edc4f5554e1d173945160b7deaca92e61d7a755.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Then we move the pointer onto the first unread track, and repeat the algorithm for <span class=\"tex-span\"><i>h</i>[<i>i</i> + 1]</span>, and so on with each head.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/3342f24e1fd6ab939313f6d6278245c95d89544f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a>.</p><p><strong>Bonus:</strong> The problem is completely real, if the disk has only a single head, if we know, what tracks should be read; then the optimal algorithm chooses between the two choices described above. I and <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a> were listening this on a lecture, and created the given problem out of boredom ;]</p><h4><a href=\"/contest/343/problem/D\" title=\"Codeforces Round 200 (Div. 1)\">343D - Water Tree</a></h4><p>Let's learn how to color a whole subtree. For that enumerate all vertices in post-order DFS. Then each subtree covers a single continious vertex number segment. For each vertex we store the bounds of such segment for a subtree with a root in this vertex. Then to color a subtree means to color a segment in a segment tree.</p><p>Then create a segment tree that has a following property: if a vertex <span class=\"tex-span\"><i>v</i></span> was emptied, and is still empty, then this vertex is colored in the segment tree. In the beginning "empty" all the vertices. That is, color all the vertices in the segment tree. With this tree we can efficiently process the queries:</p> <ol> <li><p>Fill a vertex <span class=\"tex-span\"><i>v</i></span>. Clean the interval for the subtree of <span class=\"tex-span\"><i>v</i></span>. If before that some vertex of a subtree was empty, color the parent of <span class=\"tex-span\"><i>v</i></span>.</p></li> <li><p>Empty a vertex <span class=\"tex-span\"><i>v</i></span>. Color the vertex <span class=\"tex-span\"><i>v</i></span> in the segment tree.</p></li> <li><p>Reply whether a vertex <span class=\"tex-span\"><i>v</i></span> is filled. If in the segment tree at least one vertex is colored, then there is such a descendant of <span class=\"tex-span\"><i>v</i></span> that is empty now, so the vertex <span class=\"tex-span\"><i>v</i></span> is not filled.</p></li> </ol><p><a class=\"rated-user user-blue\" href=\"/profile/Shtrix\" title=\"Expert Shtrix\">Shtrix</a> noted that essentially the same solution can be implemented with only a single set.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fcb5cb34164112e0db4b3ef4b921f55df7ffb005.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> Some participants could see the similarities with a problem Ball Machine from BOI 2013, but the solutions to the both problems are quite different.</p><h4><a href=\"/contest/343/problem/E\" title=\"Codeforces Round 200 (Div. 1)\">343E - Pumping Stations</a></h4><p>In this problem we are asked to find such graph vertex permutation that maximizes the sum of the maximum flows sent between each two consequtive vertices in the permutation.</p><p>The problem can be solved with <a href=\"https://en.wikipedia.org/wiki/Gomory%E2%80%93Hu_tree\">Gomory-Hu</a> tree data structure. For a given weighted graph the tree has the following properties:</p> <ol> <li>The vertex set of the tree and the graph is the same.</li> <li>The maximum flow between vertices <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> in the tree is equal to the maximum flow in the graph.</li> </ol><p>Surprisingly, such a tree exists for any weighted graph, and can be built in <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. It appears that the answer to the problem is equal to the sum of the edge weights in this tree.</p><p>We prove this statement by induction on the number of the tree vertices. Pick the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> with the smallest weight in the tree. Consider that in an optimal permutation more than one path between two adjacent verteces in the permutation passes through this edge. Erase all these paths, then each of the <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> subtrees holds a set of disjoint remaining paths from the permutation. For each set, join all the paths in one chain, obtaining two chains. These chains we join by a path <span class=\"tex-span\"><i>s</i></span> that goes trough the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>. Thus we have built a permutation that is not worse than the considered one. For a path <span class=\"tex-span\"><i>s</i></span> the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> is the smallest, so the flow along this path is equal to the weight of this edge. It follows from the induction that in subtrees <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> the answer is equal to the sum of edges. By adding the weight of edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>, we get the desired result.</p><p>From the last paragraph it is clear how to build such a permutation: take the smallest edge, obtain two chains from the vertex subtrees recursively, and add them together to form a one chain. Since there are not many vertices, we can do this part in <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-orange\" href=\"/profile/Gerald\" title=\"Master Gerald\">Gerald</a>.</p><p><strong>Bonus:</strong> Shortly before the contest we decided to make the constraints more loyal, so some solution that find Gomory-Hu tree by finding flow <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> times also passed. We hope that nobody is particularly saddened by this fact. (;</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/343\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/344\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-8915\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"8860\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=200\" class=\"tag notice\" style=\"text-decoration: none;\">200</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+64</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8860#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8860#comments\">\n 53\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8931\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (43)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145823\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bipinb1994\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/91315/avatar/b4e2d8ac5b2569a3.jpg'/> </a>\n <div><a href=\"/profile/bipinb1994\" title=\"Expert bipinb1994\" class=\"rated-user user-blue\">bipinb1994</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 07:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145823\" href=\"?#comment-145823\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145823\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-15\"\r\n data-commentUserId=\"91315\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145823\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hai this was my first round in Codeforces. But my code was not accepted and it says that it was wrong with the 3rd test case. What i did was put a loop from 0 to n-1 and i checked ch[i][!=ch[i+1][0] then count++; else continue where 'ch' is the character array(2-D) whose size was Nx3 ...Is this algorithm completely wrong. As i said this was the first round here i did not understand what is wrong with this. If possible please do tell me what is wrong with this algorithm..:(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145823 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145823 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145823\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145863\" commentParentId=\"145823\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 14:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145863\" href=\"?#comment-145863\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145823\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145863\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145863\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please look at link <a href=\"//codeforces.com/contest/344/submission/4461494\">http://codeforces.com/contest/344/submission/4461494</a>. </p><p>The log says</p><p>Time: 0 ms, memory: 0 KB Verdict: WRONG_ANSWER Input 1 10 Output 0 Answer 1 Checker comment wrong answer 1st numbers differ — expected: '1', found: '0'</p><p>I believe this should be self explanatory. </p><p>Also it would help playing around with the system before trying to enter a rated match.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145863 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145863 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145863\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146026\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ka16\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ka16\" title=\"Pupil ka16\" class=\"rated-user user-green\">ka16</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 06:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146026\" href=\"?#comment-146026\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146026\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"12131\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146026\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody please clarify the two choices of head(s) in the solution of 343C-Read Time problem above? I couldn't understand it completely. Thank in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146026 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146026 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146026\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146037\" commentParentId=\"146026\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hriss95\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27396/avatar/d6cec8eac7bdbde3.jpg'/> </a>\n <div><a href=\"/profile/hriss95\" title=\"Expert hriss95\" class=\"rated-user user-blue\">hriss95</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 13:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146037\" href=\"?#comment-146037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146026\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146037\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"27396\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have to choose one of the two types moving: first to the right or first to the left. You have to use the one which covers more points to the right. Note that both types of moving cover the left point and that's why you have to take as much as points as you can to the right.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146037\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sorin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/sorin\" title=\"Expert sorin\" class=\"rated-user user-blue\">sorin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 12:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146034\" href=\"?#comment-146034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"124904\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody give me a hint for the bonus at Div2 — B? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146034\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146064\" commentParentId=\"146034\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 21:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146064\" href=\"?#comment-146064\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146034\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146064\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146064\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Think greedy ;]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146064 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146064 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146064\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"152157\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ghooo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2010/avatar/659a8aca8b12506a.jpg'/> </a>\n <div><a href=\"/profile/ghooo\" title=\"Master ghooo\" class=\"rated-user user-orange\">ghooo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/26/2013 08:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-152157\" href=\"?#comment-152157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"152157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2010\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-152157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>will the connections between the atoms be circular? like 1 <-> 2 <-> 3 <-> 4 <-> 5 ... n <-> 1 (again) ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-152157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-152157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-152157\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"521750\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/n0tred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1177564/avatar/a46e0281e87dd6c9.jpg'/> </a>\n <div><a href=\"/profile/n0tred\" title=\"Candidate Master n0tred\" class=\"rated-user user-violet\">n0tred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/25/2019 14:29\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-521750\" href=\"?#comment-521750\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"521750\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1177564\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-521750\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you give a better hint? (Maybe through a spoiler, I suppose)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-521750 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-521750 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-521750\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"523308\" commentParentId=\"521750\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/29/2019 09:36\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-523308\" href=\"?#comment-523308\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-521750\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"523308\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-523308\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the algorithm that continuously connects the vertex with the smallest degree with the vertex with the largest degree works (here by degree I mean the unconnected edges), and builds a connected graph. I think this can be proved by induction.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-523308 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-523308 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-523308\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146129\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 11:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146129\" href=\"?#comment-146129\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146129\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146129\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think there is an issue with Problem 343A — Rational Resistance. Here according to the editorial the answer to the ratio 6/5 would be 6(I have verified this with an accepted solution). But this ratio can be achieved with a resistance of 2 and 3 in parallel, which makes the number of resistors required equal to 5 which would imply the editorial and the system tests to be wrong.</p><p>Am I missing something here?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146129 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146129 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146129\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146259\" commentParentId=\"146129\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146259\" href=\"?#comment-146259\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146129\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146259\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146259\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think it's because the definition of <strong>one element</strong> only let you add <strong>one</strong> new unit resistor to another element</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146259 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146259 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146259\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146256\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146256\" href=\"?#comment-146256\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146256\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146256\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for the nice problems!</p><p>I just have a little question on 343C — Read Time. I use the same algorithm and get AC, but my algorithm is running at O(n log^2 n)... as for the step: "Then we move the pointer onto the first unread track" I use another binary search...</p><p>how can I implement the same algorithm with O(n log n) as said in editorial? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146256 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146256 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146256\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146269\" commentParentId=\"146256\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146269\" href=\"?#comment-146269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146256\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146269\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We hold two pointers: the first points at the first unread track from the left, and the second points at the first unused head so far. So we take this head and read with its help the maximum number of yet unread tracks (note that they are consequent and begin at the first pointer) according to the best of the two choices described in tutorial. Then we move the first pointer to the first yet unread track, and increment the second by one. Thus each pointer moves <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> times in this iteration of the binary search. Take also in consideration that some heads can be not used at all.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154161\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/s2k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146708/avatar/ec43946f377e5c64.jpg'/> </a>\n <div><a href=\"/profile/s2k\" title=\"Newbie s2k\" class=\"rated-user user-gray\">s2k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154161\" href=\"?#comment-154161\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154161\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146708\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154161\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi. I was just trying to solve problem A of division 2, but was unsuccessful after hours of effort. I eventually lost patience and decided to see the codes of others. I did understand what was going in the code, but couldn't figure out why this method was chosen in the first place. Can someone please help me understand the solution?</p><p>P.S. I'm a newbie with almost no prior knowledge about number theory. :$</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154161 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154161 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154161\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154163\" commentParentId=\"154161\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154163\" href=\"?#comment-154163\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-154161\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154163\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154163\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The number of islands is always one more than the number of splits between two neighboring dominoes. One can easily convince himself by looking at an image in the description.</p><p>There are 4 possibilities of neighboring dominoes:</p> <ul> <li>01 and 01: these attract, so they don't form a split and we don't care about them</li> <li>10 and 10: these attract, so they don't form a split and we don't care about them</li> <li>01 and 10: these don't attract, so they form a split</li> <li>10 and 01: these don't attract, so they form a split</li> </ul><p>So, we can deduce that we're only interested in neighboring dominoes that are different. This means we can just count the number of indexes i (1 <= i < N) such that s[i] != s[i+1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154163 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154163 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154163\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176652\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/S.Ged\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67184/avatar/a38f51555a40b56a.jpg'/> </a>\n <div><a href=\"/profile/S.Ged\" title=\"Candidate Master S.Ged\" class=\"rated-user user-violet\">S.Ged</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 04:10\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176652\" href=\"?#comment-176652\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"176652\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"176652\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"67184\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176652\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm confused by the first sentence of 343A — Rational Resistance tutorial</p><p>How can we obtain a/(a+b) with k+1 resistors if obatined a/b wiht k resistors ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176652 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176652 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176652\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176656\" commentParentId=\"176652\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/afrizal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/103639/avatar/206f6cf479b00060.jpg'/> </a>\n <div><a href=\"/profile/afrizal\" title=\"Expert afrizal\" class=\"rated-user user-blue\">afrizal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 07:05\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176656\" href=\"?#comment-176656\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176652\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"176656\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"103639\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176656\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Remember a/a is 1. If we have a/b resistance, put one more resistor parallel will give <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c1a16b55f7f10840909e0e5863ae3ce22e36c85b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176656 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176656 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176656\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"189636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/namikaze\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/227989/avatar/51e67e9e139a65f2.jpg'/> </a>\n <div><a href=\"/profile/namikaze\" title=\"Unrated, namikaze\" class=\"rated-user user-black\">namikaze</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/28/2014 15:45\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-189636\" href=\"?#comment-189636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"189636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"227989\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-189636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><code>adding one resistor means performing one operation backwards in Euclidean algorithm</code></p><p>Can someone explain this ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-189636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-189636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-189636\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"277029\" commentParentId=\"189636\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TomBombadil\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/106415/avatar/ed9d8ef375273241.jpg'/> </a>\n <div><a href=\"/profile/TomBombadil\" title=\"Specialist TomBombadil\" class=\"rated-user user-cyan\">TomBombadil</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2016 17:50\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-277029\" href=\"?#comment-277029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-189636\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"277029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"106415\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-277029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-orange\" href=\"/profile/gen\" title=\"Master gen\">gen</a> ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-277029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-277029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-277029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"351231\" commentParentId=\"277029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/R.A.X\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/122476/avatar/686763c746ac6e7b.jpg'/> </a>\n <div><a href=\"/profile/R.A.X\" title=\"Specialist R.A.X\" class=\"rated-user user-cyan\">R.A.X</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/27/2017 15:37\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-351231\" href=\"?#comment-351231\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-277029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"351231\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"351231\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"122476\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-351231\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Suppose you have resistance of(17/3), it could be formed by adding 1 + (14/3). If you have resistance of (3/17), it could be obtained by combining resistance of 1 and 3/14 in parallel.</p><p>In terms of variable, a/b could be obtained by 1 + resistors required to create ( a-b)/b resistance, assuming a>b. and a/b if b>a, could be obtained by 1 + resistors required to create ( a/(b-a) ).</p><p>Assuming a>b so resistorRequired(a,b) = 1 + resistorRequired(a-b,b).</p> <pre>resistorReqiored(a-b,b) = 1 + resistorRequired(a-2b,b)</pre><p>............</p> <pre>resistorRequired(a-(q-1)*b ,b) = 1 + resistorRequired(a-q*b,b)</pre><p>let say r = a-q*b == a%b now at this point, one resistance needs to be connected in parallel to the b/r resistance.</p><p>so again problem becomes calculating the requiredResistance(b,r) similar to above problem,</p><p>which is similar to the gcd problem.</p><p>Hope that helps.</p><p>Why it's like gcd(a,b) = gcd(a-b,b) =gcd(a-2b,b) .... </p><p>In case of gcd(a,b) = gcd(a-b,b)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-351231 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-351231 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-351231\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"393063\" commentParentId=\"351231\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ShafinKhadem\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/508696/avatar/1b5c8ae9cf51dc77.jpg'/> </a>\n <div><a href=\"/profile/ShafinKhadem\" title=\"Master ShafinKhadem\" class=\"rated-user user-orange\">ShafinKhadem</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/01/2017 09:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-393063\" href=\"?#comment-393063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-351231\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"393063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"508696\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-393063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for the nice explanation. Now the use of euclidian algorithm to solve this problem makes sense to me.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-393063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-393063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-393063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"220282\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CloverAsta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207753/avatar/45b71a38344fa830.jpg'/> </a>\n <div><a href=\"/profile/CloverAsta\" title=\"Expert CloverAsta\" class=\"rated-user user-blue\">CloverAsta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/01/2015 14:33\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-220282\" href=\"?#comment-220282\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"220282\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207753\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-220282\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain to me the solution for Problem C div2 I understand the transition from <code>k</code> to <code>k + 1</code> but the part about Euclidean algorithm is beyond me</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-220282 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-220282 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-220282\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"232136\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anajin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221428/avatar/b8f5979933e2ce3d.jpg'/> </a>\n <div><a href=\"/profile/anajin\" title=\"Expert anajin\" class=\"rated-user user-blue\">anajin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/03/2015 14:15\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-232136\" href=\"?#comment-232136\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"232136\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-232136\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>water tree can be solved by heavy-light decomposition...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-232136 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-232136 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-232136\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"454886\" commentParentId=\"232136\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cai_lw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/325977/avatar/202b61935928944.jpg'/> </a>\n <div><a href=\"/profile/cai_lw\" title=\"International Master cai_lw\" class=\"rated-user user-orange\">cai_lw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/30/2018 20:04\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-454886\" href=\"?#comment-454886\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-232136\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"454886\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"454886\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"325977\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-454886\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, this is almost the most standard problem for HLD. But their solution is cleverer and has lower time complexity. HLD is a little bit overkill for such simple operations.</p><p>Nevertheless, HLD can pass the test. My HLD solution passed in 900ms.</p><p>Also HLD was a relatively unknown algorithm to the CP community 5 years ago.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-454886 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-454886 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-454886\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"634570\" commentParentId=\"454886\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Suri429\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/776807/avatar/90399ec92a81320a.jpg'/> </a>\n <div><a href=\"/profile/Suri429\" title=\"Master Suri429\" class=\"rated-user user-orange\">Suri429</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2020 08:55\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-634570\" href=\"?#comment-634570\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-454886\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"634570\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"776807\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-634570\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain how to approach this with HLD? I am new to HLD, and not able to get any clue here. </p><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-634570 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-634570 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-634570\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"312598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/29/2016 12:31\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-312598\" href=\"?#comment-312598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"312598\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"312598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-312598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder why I did wrong in the implementation of lazy propagation for Div1D, could anyone kindly lend some help? </p><p><a href=\"//codeforces.com/contest/343/submission/20226349\">http://codeforces.com/contest/343/submission/20226349</a></p><p>Thanks in advance. =)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-312598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-312598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-312598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"357445\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anshulgarg19\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/anshulgarg19\" title=\"Pupil anshulgarg19\" class=\"rated-user user-green\">anshulgarg19</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/02/2017 20:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-357445\" href=\"?#comment-357445\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"357445\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"244328\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-357445\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Accepted solution for the problem 343A Rational Resistance would give 6 as the output for input a = 10 and b = 7 i.e.10/7. But, if we have 5 ohm and 2 ohm resistors in parallel, then we have the same resistance value 10/7. So minimum value should be 2 resistors for this case. Kindly explain if i am wrong in understanding the problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-357445 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-357445 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-357445\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360009\" commentParentId=\"357445\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/snehil10\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/351506/avatar/522f61633a219a3b.jpg'/> </a>\n <div><a href=\"/profile/snehil10\" title=\"Expert snehil10\" class=\"rated-user user-blue\">snehil10</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/14/2017 10:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360009\" href=\"?#comment-360009\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-357445\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"360009\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"351506\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360009\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have only 1-ohm resistors in the beginning. Thus it requires 5 1-ohm resistors to make a 5-ohm resistor, and 2 1-ohm resistors to make a 2-ohm resistor. So according to you answer is 7 and not 2.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360009 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360009 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360009\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371475\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rush_123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/rush_123\" title=\"Expert rush_123\" class=\"rated-user user-blue\">rush_123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/03/2017 17:42\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371475\" href=\"?#comment-371475\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"371475\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"439840\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371475\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 343D — Water Tree query 1 and 2 can be solved using a dfs to find in time and out time for every node and then using segment tree But what about 3rd query how to solve it?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371475 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371475 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371475\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"422269\" commentParentId=\"371475\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stringray\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/575608/avatar/2902babcf56868a2.jpg'/> </a>\n <div><a href=\"/profile/stringray\" title=\"Expert stringray\" class=\"rated-user user-blue\">stringray</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/28/2018 16:13\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-422269\" href=\"?#comment-422269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371475\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"422269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"575608\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-422269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yeah same question .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-422269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-422269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-422269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"437012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ragnarok_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ragnarok_\" title=\"Newbie ragnarok_\" class=\"rated-user user-gray\">ragnarok_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2018 08:59\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-437012\" href=\"?#comment-437012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"437012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"673189\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-437012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Q.343A can anybody explain me why min resistor for 199/200 is 200.....it can be also constructed using 101 resistors(1/2+1/4+1/5+1/40+1/50)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-437012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-437012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-437012\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"573631\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SLIMSHADYNICK\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/598862/avatar/7629f1b29f0fe807.jpg'/> </a>\n <div><a href=\"/profile/SLIMSHADYNICK\" title=\"Candidate Master SLIMSHADYNICK\" class=\"rated-user user-violet\">SLIMSHADYNICK</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2020 21:03\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-573631\" href=\"?#comment-573631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"573631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"598862\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-573631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>correct!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-573631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-573631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-573631\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587715\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pied-piper\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/754580/avatar/a6fb81d49bb96665.jpg'/> </a>\n <div><a href=\"/profile/pied-piper\" title=\"Expert pied-piper\" class=\"rated-user user-blue\">pied-piper</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/11/2020 16:14\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587715\" href=\"?#comment-587715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"587715\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"587715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"754580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It is because they are separate elements and hence they cannot be added together. Only an element and a 1 unit resistance can be added in series(or parallel)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587715\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"791297\" commentParentId=\"587715\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/15/2021 17:25\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-791297\" href=\"?#comment-791297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587715\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"791297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-791297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-791297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-791297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-791297\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"598229\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayank_ag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/644568/avatar/c1136e364e721d18.jpg'/> </a>\n <div><a href=\"/profile/mayank_ag\" title=\"Master mayank_ag\" class=\"rated-user user-orange\">mayank_ag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/05/2020 20:53\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-598229\" href=\"?#comment-598229\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"598229\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"644568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-598229\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>An alternate approach for solving D: Use of lazy segment tree over HLD & Euler path. For every filling, fill Euler path with current query number, and for emptying, fill HLD path from the root with query number. For queries, check which of the seg tree has high query number.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-598229 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-598229 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-598229\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"600816\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Asterix_11\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Asterix_11\" title=\"Pupil Asterix_11\" class=\"rated-user user-green\">Asterix_11</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/11/2020 00:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-600816\" href=\"?#comment-600816\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"600816\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1472760\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-600816\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem 344A</p> <pre><code>#include <iostream>\nusing namespace std;\nint main()\n{\n int a, i, b[100], ans;\n scanf("%d", &a);\n for(i = 0; i < a; ++i){\n scanf("%d", &b[i]);\n }\n ans = 1;\n for(i = 0; i < (a-1); ++i){\n if(b[i] != b[i + 1]){\n ++ans;}\n }\n printf("%d", ans);\n return 0;\n}\n</code></pre><p>This is my code, but I don't know how to improve it, so that the time limit won't be a problem anymore. Any help?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-600816 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-600816 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-600816\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752098\" commentParentId=\"600816\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 09:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752098\" href=\"?#comment-752098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-600816\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can make two variable for prev and current value and if they are not equal you can increment it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752098\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752075\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:25\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752075\" href=\"?#comment-752075\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752075\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752075\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Problem C, if more than one of the elements can be in parallel than for ratio 199 and 200 the answer given is 200. But we may solve this in 74. like 1/2+1/4+1/8+1/10+1/50.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752075 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752075 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752075\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752089\" commentParentId=\"752075\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752089\" href=\"?#comment-752089\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-752075\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752089\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752089\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Okay it would be like either + denominator to the numerator or + numerator to the denominator.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752089 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752089 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752089\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"946539\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mohsina_Shaikh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1396580/avatar/6f21616a2d8d578.jpg'/> </a>\n <div><a href=\"/profile/Mohsina_Shaikh\" title=\"Newbie Mohsina_Shaikh\" class=\"rated-user user-gray\">Mohsina_Shaikh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/24/2022 06:47\">13 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-946539\" href=\"?#comment-946539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"946539\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"946539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1396580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-946539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a> or <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a> or can anyone please explain <code>Alternating Current</code> Solution.Tried so hard but not able to understand it. A</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-946539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-946539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-946539\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"959164\" commentParentId=\"946539\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rishijoshi483\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2453886/avatar/1ecf48b346fe39d0.jpg'/> </a>\n <div><a href=\"/profile/rishijoshi483\" title=\"Expert rishijoshi483\" class=\"rated-user user-blue\">rishijoshi483</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/03/2022 09:44\">12 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-959164\" href=\"?#comment-959164\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-946539\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"959164\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2453886\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-959164\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try it using stack</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-959164 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-959164 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-959164\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"966651\" commentParentId=\"959164\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Yohajji\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2854745/avatar/b31d6e4c63852741.jpg'/> </a>\n <div><a href=\"/profile/Yohajji\" title=\"Newbie Yohajji\" class=\"rated-user user-gray\">Yohajji</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2022 13:35\">11 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-966651\" href=\"?#comment-966651\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-959164\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"966651\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2854745\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-966651\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>using the stack was a brilliant aproach, thank you </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-966651 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-966651 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-966651\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1039007\" commentParentId=\"966651\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AbdelrahmanMahallawy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3189297/avatar/6b2a1658ad37caa0.jpg'/> </a>\n <div><a href=\"/profile/AbdelrahmanMahallawy\" title=\"Newbie AbdelrahmanMahallawy\" class=\"rated-user user-gray\">AbdelrahmanMahallawy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/20/2023 03:36\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1039007\" href=\"?#comment-1039007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-966651\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1039007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3189297\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1039007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>anytime </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1039007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1039007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1039007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8931\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8931 = true;\r\nvar lastPreviewContent8931 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8931] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8931] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:23</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128748fcb8816ab',t:'MTY5NjcwNTk0My4yOTkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1742,"cells":{"problem_id":{"kind":"string","value":"344A"},"contest":{"kind":"string","value":"344"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Magnets"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Magnets</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike entertains himself by arranging rows of dominoes. He doesn't need dominoes, though: he uses rectangular magnets instead. Each magnet has two poles, positive (a \"plus\") and negative (a \"minus\"). If two magnets are put together at a close distance, then the like poles will repel each other and the opposite poles will attract each other.</p><p>Mike starts by laying one magnet horizontally on the table. During each following step Mike adds one more magnet horizontally to the right end of the row. Depending on how Mike puts the magnet on the table, it is either attracted to the previous one (forming a group of multiple magnets linked together) or repelled by it (then Mike lays this magnet at some distance to the right from the previous one). We assume that a sole magnet not linked to others forms a group of its own.</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/a2cfc00fa5ba91709a0c55ed4bb5e70f976b5f20.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>Mike arranged multiple magnets in a row. Determine the number of groups that the magnets formed.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100000</span>) — the number of magnets. Then <span class=\"tex-span\"><i>n</i></span> lines follow. The <span class=\"tex-span\"><i>i</i></span>-th line (<span class=\"tex-span\">1 ≤ <i>i</i> ≤ <i>n</i></span>) contains either characters \"<span class=\"tex-font-style-tt\">01</span>\", if Mike put the <span class=\"tex-span\"><i>i</i></span>-th magnet in the \"plus-minus\" position, or characters \"<span class=\"tex-font-style-tt\">10</span>\", if Mike put the magnet in the \"minus-plus\" position.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>On the single line of the output print the number of groups of magnets.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>6<br/>10<br/>10<br/>10<br/>01<br/>10<br/>10<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>01<br/>01<br/>10<br/>10<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The first testcase corresponds to the figure. The testcase has three groups consisting of three, one and two magnets.</p><p>The second testcase has two groups, each consisting of two magnets.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"6ec1b9399a5e444d15a1a14a7cec2fb2\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"97388d8e9a3336f0fbcbc9a7e735a42b6679436b\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='6ec1b9399a5e444d15a1a14a7cec2fb2'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F344%2Fproblem%2FA%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='6ec1b9399a5e444d15a1a14a7cec2fb2'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/344\">Codeforces Round 200 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='6ec1b9399a5e444d15a1a14a7cec2fb2'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/344/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *800\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='6ec1b9399a5e444d15a1a14a7cec2fb2'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3462\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='6ec1b9399a5e444d15a1a14a7cec2fb2'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3462\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8851\" title=\"Codeforces Round #200\" target=\"_blank\">Codeforces Round #200</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1854:1855\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8860\" title=\"Codeforces Round #200 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1850:1851\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/344\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/344/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/344/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/344/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/344/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/344/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/344/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/344/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_7a8324a855183c680c4b4cf964485efe4dc48426\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Magnets</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike entertains himself by arranging rows of dominoes. He doesn't need dominoes, though: he uses rectangular magnets instead. Each magnet has two poles, positive (a "plus") and negative (a "minus"). If two magnets are put together at a close distance, then the like poles will repel each other and the opposite poles will attract each other.</p><p>Mike starts by laying one magnet horizontally on the table. During each following step Mike adds one more magnet horizontally to the right end of the row. Depending on how Mike puts the magnet on the table, it is either attracted to the previous one (forming a group of multiple magnets linked together) or repelled by it (then Mike lays this magnet at some distance to the right from the previous one). We assume that a sole magnet not linked to others forms a group of its own.</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/a2cfc00fa5ba91709a0c55ed4bb5e70f976b5f20.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>Mike arranged multiple magnets in a row. Determine the number of groups that the magnets formed.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100000</span>) — the number of magnets. Then <span class=\"tex-span\"><i>n</i></span> lines follow. The <span class=\"tex-span\"><i>i</i></span>-th line (<span class=\"tex-span\">1 ≤ <i>i</i> ≤ <i>n</i></span>) contains either characters "<span class=\"tex-font-style-tt\">01</span>", if Mike put the <span class=\"tex-span\"><i>i</i></span>-th magnet in the "plus-minus" position, or characters "<span class=\"tex-font-style-tt\">10</span>", if Mike put the magnet in the "minus-plus" position.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>On the single line of the output print the number of groups of magnets.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>6<br />10<br />10<br />10<br />01<br />10<br />10<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />01<br />01<br />10<br />10<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The first testcase corresponds to the figure. The testcase has three groups consisting of three, one and two magnets.</p><p>The second testcase has two groups, each consisting of two magnets.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:40</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bd99294d9d76',t:'MTY5NjY0NjAyMC4yMDgwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Implementation problems, programming technics, simulation\"]"},"short_tags":{"kind":"string","value":"[\"implementation\", \"*800\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8860"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"21ba25574a0615e5dc71db6e32a512d8\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #200 Tutorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #200 Tutorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='21ba25574a0615e5dc71db6e32a512d8'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8860\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/gen\">gen</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gen\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gen\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gen\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gen\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gen\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gen\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gen\" style=\"text-decoration:none;color:black !important;\">gen's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8915\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8860\"> <p>Codeforces Round #200 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a>,\r\n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h4><a href=\"/contest/344/problem/A\" title=\"Codeforces Round 200 (Div. 2)\">344A - Magnets</a></h4><p>By the definition each block consists of a number of consequent and equally oriented dominoes. That means that in places where adjacent dominoes are not oriented equally, one block ends and another block starts. So, if there are <span class=\"tex-span\"><i>x</i></span> such places, the answer is equal to <span class=\"tex-span\"><i>x</i> + 1</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> The problem was created a day before the contest and filled in the last part of a physically flavoured DivII complect. :]</p><h4><a href=\"/contest/344/problem/B\" title=\"Codeforces Round 200 (Div. 2)\">344B - Simple Molecules</a></h4><p>First solution. First, the sum <span class=\"tex-span\"><i>a</i> + <i>b</i> + <i>c</i></span> should be even, since each bond adds 2 to the sum. Now let <span class=\"tex-span\"><i>x</i></span>, <span class=\"tex-span\"><i>y</i></span>, <span class=\"tex-span\"><i>z</i></span> be the number of bonds between 1st and 2nd, 2nd and 3rd, 3rd and 1st atoms, accordingly. So we have to solve the system <span class=\"tex-span\"><i>x</i> + <i>z</i> = <i>a</i></span>, <span class=\"tex-span\"><i>y</i> + <i>x</i> = <i>b</i></span>, <span class=\"tex-span\"><i>z</i> + <i>y</i> = <i>c</i></span>. Now observe that the solution to the system is the length of the tangents on the triangle with sides of length <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span> to its inscribed circle, and are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/2cee22ffa44dda3ce1b315e8cceef38c6288cf2c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1aed1c363b13d01e1b412b9cd3d5e34d19eb9c96.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/30fbfc651674588cadbee1fedd1e4b0d08d1ad4e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. If the problem asked only the possibility of building such a molecule, we could just check if there exists (possibly degenerate) triangle with sides <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span>.</p><p><img alt=\" \" src=\"/predownloaded/e3/d3/e3d3c930f4f93ca68c1e61630a2771472ecbd60a.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Second solution. Bruteforce all <span class=\"tex-span\"><i>x</i></span> values. For a fixed <span class=\"tex-span\"><i>x</i></span> values of <span class=\"tex-span\"><i>y</i></span> and <span class=\"tex-span\"><i>z</i></span> are defined uniquely: <span class=\"tex-span\"><i>y</i> = <i>b</i> - <i>x</i></span>, <span class=\"tex-span\"><i>z</i> = <i>a</i> - <i>x</i></span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(1) / <i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> Can you solve the problem for any vertex number <span class=\"tex-span\"><i>n</i></span>? When and how can such a graph be built?</p><h4><a href=\"/contest/343/problem/A\" title=\"Codeforces Round 200 (Div. 1)\">343A - Rational Resistance</a></h4><p>If a fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> can be obtained with <span class=\"tex-span\"><i>k</i></span> resistors, then it is simple to calculate that we can obtain fractions <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b6913fd8136f518e8a7898a9b759b74c4d483101.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/daf9572f0aa7677d7961c329e6277818df63bd9f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> with <span class=\"tex-span\"><i>k</i> + 1</span> resistors. So adding one resistor means performing one operation backwards in Euclidean algorithm. That means that the answer is equal to the number of steps in standard Euclidean algorithm.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e847ae811adbd761fa24db4ba7a6827e0806d670.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Бонус:</strong> At first we thought about the major problem (any two elements can be joined), but had a moment of eureka and got that the given problem unexpectedly naturally can be reduced to GCD. By the way, the result tree — <a href=\"https://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree\">http://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree</a>.</p><h4><a href=\"/contest/343/problem/B\" title=\"Codeforces Round 200 (Div. 1)\">343B - Alternating Current</a></h4><p>Let us solve the following problem first: we are given a string of symbols A and B. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>A</i></span>, then at the <span class=\"tex-span\"><i>i</i></span>-th step the upper wire (see figure) is being put over the lower wire. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>B</i></span>, the lower wire is being put over the upper wire at <span class=\"tex-span\"><i>i</i></span>-th step. Observe that if some two symbols <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are adjacent, we can untangle this place, throw the symbols out and obtain the string of length two symbols less. So the wires can be untangled iff the number of A's and B's in the string is the same. The given problem can be reduced to the described in a following fashion: in each odd position we change – to B and + to A. In each even position we change — to A and + to B. The reduction is correct, since on each even position the order of — and + are always swapped, and in each odd position their order is the same as in the beginning.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> If you are interested by this problem, you can learn about the braid theory <a href=\"https://en.wikipedia.org/wiki/Braid_theory\">http://en.wikipedia.org/wiki/Braid_theory</a> :] Fun fact: a harder version of this problem was planned already for Round #142, but the error in solution idea was found, and the problem was left to lay for almost a year.</p><h4><a href=\"/contest/343/problem/C\" title=\"Codeforces Round 200 (Div. 1)\">343C - Read Time</a></h4><p>Let's search the answer <span class=\"tex-span\"><i>t</i></span> with the binary search. Fix some value of <span class=\"tex-span\"><i>t</i></span>. Look at the first head from the left <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> that can read track <span class=\"tex-span\"><i>p</i>[0]</span>. If <span class=\"tex-span\"><i>p</i>[0] > <i>h</i>[<i>i</i>]</span>, then <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> goes to the right <span class=\"tex-span\"><i>t</i></span> seconds and reads all tracks on its way. Otherwise if <span class=\"tex-span\"><i>p</i>[0] ≤ <i>h</i>[<i>i</i>]</span>, then the head has two choices:</p> <ol> <li>go to the right <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> seconds, then <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> to the left and <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> again to the left;</li> <li>go to the left <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> seconds, then <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> to the right and <span class=\"tex-span\"><i>t</i> - 2·(<i>h</i>[<i>i</i>] - <i>p</i>[0])</span> again to the right.</li> </ol><p>Obviously, for <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> it is more advantageous to visit the track positioned as much as possible to the right. So we choose by <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7edc4f5554e1d173945160b7deaca92e61d7a755.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Then we move the pointer onto the first unread track, and repeat the algorithm for <span class=\"tex-span\"><i>h</i>[<i>i</i> + 1]</span>, and so on with each head.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/3342f24e1fd6ab939313f6d6278245c95d89544f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a>.</p><p><strong>Bonus:</strong> The problem is completely real, if the disk has only a single head, if we know, what tracks should be read; then the optimal algorithm chooses between the two choices described above. I and <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a> were listening this on a lecture, and created the given problem out of boredom ;]</p><h4><a href=\"/contest/343/problem/D\" title=\"Codeforces Round 200 (Div. 1)\">343D - Water Tree</a></h4><p>Let's learn how to color a whole subtree. For that enumerate all vertices in post-order DFS. Then each subtree covers a single continious vertex number segment. For each vertex we store the bounds of such segment for a subtree with a root in this vertex. Then to color a subtree means to color a segment in a segment tree.</p><p>Then create a segment tree that has a following property: if a vertex <span class=\"tex-span\"><i>v</i></span> was emptied, and is still empty, then this vertex is colored in the segment tree. In the beginning "empty" all the vertices. That is, color all the vertices in the segment tree. With this tree we can efficiently process the queries:</p> <ol> <li><p>Fill a vertex <span class=\"tex-span\"><i>v</i></span>. Clean the interval for the subtree of <span class=\"tex-span\"><i>v</i></span>. If before that some vertex of a subtree was empty, color the parent of <span class=\"tex-span\"><i>v</i></span>.</p></li> <li><p>Empty a vertex <span class=\"tex-span\"><i>v</i></span>. Color the vertex <span class=\"tex-span\"><i>v</i></span> in the segment tree.</p></li> <li><p>Reply whether a vertex <span class=\"tex-span\"><i>v</i></span> is filled. If in the segment tree at least one vertex is colored, then there is such a descendant of <span class=\"tex-span\"><i>v</i></span> that is empty now, so the vertex <span class=\"tex-span\"><i>v</i></span> is not filled.</p></li> </ol><p><a class=\"rated-user user-blue\" href=\"/profile/Shtrix\" title=\"Expert Shtrix\">Shtrix</a> noted that essentially the same solution can be implemented with only a single set.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fcb5cb34164112e0db4b3ef4b921f55df7ffb005.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> Some participants could see the similarities with a problem Ball Machine from BOI 2013, but the solutions to the both problems are quite different.</p><h4><a href=\"/contest/343/problem/E\" title=\"Codeforces Round 200 (Div. 1)\">343E - Pumping Stations</a></h4><p>In this problem we are asked to find such graph vertex permutation that maximizes the sum of the maximum flows sent between each two consequtive vertices in the permutation.</p><p>The problem can be solved with <a href=\"https://en.wikipedia.org/wiki/Gomory%E2%80%93Hu_tree\">Gomory-Hu</a> tree data structure. For a given weighted graph the tree has the following properties:</p> <ol> <li>The vertex set of the tree and the graph is the same.</li> <li>The maximum flow between vertices <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> in the tree is equal to the maximum flow in the graph.</li> </ol><p>Surprisingly, such a tree exists for any weighted graph, and can be built in <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. It appears that the answer to the problem is equal to the sum of the edge weights in this tree.</p><p>We prove this statement by induction on the number of the tree vertices. Pick the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> with the smallest weight in the tree. Consider that in an optimal permutation more than one path between two adjacent verteces in the permutation passes through this edge. Erase all these paths, then each of the <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> subtrees holds a set of disjoint remaining paths from the permutation. For each set, join all the paths in one chain, obtaining two chains. These chains we join by a path <span class=\"tex-span\"><i>s</i></span> that goes trough the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>. Thus we have built a permutation that is not worse than the considered one. For a path <span class=\"tex-span\"><i>s</i></span> the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> is the smallest, so the flow along this path is equal to the weight of this edge. It follows from the induction that in subtrees <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> the answer is equal to the sum of edges. By adding the weight of edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>, we get the desired result.</p><p>From the last paragraph it is clear how to build such a permutation: take the smallest edge, obtain two chains from the vertex subtrees recursively, and add them together to form a one chain. Since there are not many vertices, we can do this part in <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-orange\" href=\"/profile/Gerald\" title=\"Master Gerald\">Gerald</a>.</p><p><strong>Bonus:</strong> Shortly before the contest we decided to make the constraints more loyal, so some solution that find Gomory-Hu tree by finding flow <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> times also passed. We hope that nobody is particularly saddened by this fact. (;</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/343\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/344\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-8915\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"8860\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=200\" class=\"tag notice\" style=\"text-decoration: none;\">200</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+64</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8860#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8860#comments\">\n 53\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8931\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (43)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145823\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bipinb1994\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/91315/avatar/b4e2d8ac5b2569a3.jpg'/> </a>\n <div><a href=\"/profile/bipinb1994\" title=\"Expert bipinb1994\" class=\"rated-user user-blue\">bipinb1994</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 07:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145823\" href=\"?#comment-145823\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145823\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-15\"\r\n data-commentUserId=\"91315\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145823\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hai this was my first round in Codeforces. But my code was not accepted and it says that it was wrong with the 3rd test case. What i did was put a loop from 0 to n-1 and i checked ch[i][!=ch[i+1][0] then count++; else continue where 'ch' is the character array(2-D) whose size was Nx3 ...Is this algorithm completely wrong. As i said this was the first round here i did not understand what is wrong with this. If possible please do tell me what is wrong with this algorithm..:(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145823 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145823 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145823\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145863\" commentParentId=\"145823\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 14:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145863\" href=\"?#comment-145863\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145823\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145863\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145863\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please look at link <a href=\"//codeforces.com/contest/344/submission/4461494\">http://codeforces.com/contest/344/submission/4461494</a>. </p><p>The log says</p><p>Time: 0 ms, memory: 0 KB Verdict: WRONG_ANSWER Input 1 10 Output 0 Answer 1 Checker comment wrong answer 1st numbers differ — expected: '1', found: '0'</p><p>I believe this should be self explanatory. </p><p>Also it would help playing around with the system before trying to enter a rated match.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145863 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145863 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145863\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146026\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ka16\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ka16\" title=\"Pupil ka16\" class=\"rated-user user-green\">ka16</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 06:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146026\" href=\"?#comment-146026\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146026\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"12131\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146026\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody please clarify the two choices of head(s) in the solution of 343C-Read Time problem above? I couldn't understand it completely. Thank in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146026 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146026 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146026\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146037\" commentParentId=\"146026\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hriss95\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27396/avatar/d6cec8eac7bdbde3.jpg'/> </a>\n <div><a href=\"/profile/hriss95\" title=\"Expert hriss95\" class=\"rated-user user-blue\">hriss95</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 13:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146037\" href=\"?#comment-146037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146026\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146037\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"27396\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have to choose one of the two types moving: first to the right or first to the left. You have to use the one which covers more points to the right. Note that both types of moving cover the left point and that's why you have to take as much as points as you can to the right.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146037\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sorin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/sorin\" title=\"Expert sorin\" class=\"rated-user user-blue\">sorin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 12:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146034\" href=\"?#comment-146034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"124904\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody give me a hint for the bonus at Div2 — B? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146034\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146064\" commentParentId=\"146034\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 21:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146064\" href=\"?#comment-146064\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146034\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146064\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146064\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Think greedy ;]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146064 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146064 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146064\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"152157\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ghooo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2010/avatar/659a8aca8b12506a.jpg'/> </a>\n <div><a href=\"/profile/ghooo\" title=\"Master ghooo\" class=\"rated-user user-orange\">ghooo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/26/2013 08:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-152157\" href=\"?#comment-152157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"152157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2010\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-152157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>will the connections between the atoms be circular? like 1 <-> 2 <-> 3 <-> 4 <-> 5 ... n <-> 1 (again) ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-152157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-152157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-152157\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"521750\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/n0tred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1177564/avatar/a46e0281e87dd6c9.jpg'/> </a>\n <div><a href=\"/profile/n0tred\" title=\"Candidate Master n0tred\" class=\"rated-user user-violet\">n0tred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/25/2019 14:29\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-521750\" href=\"?#comment-521750\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"521750\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1177564\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-521750\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you give a better hint? (Maybe through a spoiler, I suppose)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-521750 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-521750 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-521750\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"523308\" commentParentId=\"521750\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/29/2019 09:36\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-523308\" href=\"?#comment-523308\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-521750\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"523308\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-523308\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the algorithm that continuously connects the vertex with the smallest degree with the vertex with the largest degree works (here by degree I mean the unconnected edges), and builds a connected graph. I think this can be proved by induction.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-523308 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-523308 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-523308\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146129\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 11:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146129\" href=\"?#comment-146129\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146129\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146129\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think there is an issue with Problem 343A — Rational Resistance. Here according to the editorial the answer to the ratio 6/5 would be 6(I have verified this with an accepted solution). But this ratio can be achieved with a resistance of 2 and 3 in parallel, which makes the number of resistors required equal to 5 which would imply the editorial and the system tests to be wrong.</p><p>Am I missing something here?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146129 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146129 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146129\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146259\" commentParentId=\"146129\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146259\" href=\"?#comment-146259\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146129\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146259\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146259\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think it's because the definition of <strong>one element</strong> only let you add <strong>one</strong> new unit resistor to another element</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146259 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146259 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146259\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146256\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146256\" href=\"?#comment-146256\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146256\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146256\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for the nice problems!</p><p>I just have a little question on 343C — Read Time. I use the same algorithm and get AC, but my algorithm is running at O(n log^2 n)... as for the step: "Then we move the pointer onto the first unread track" I use another binary search...</p><p>how can I implement the same algorithm with O(n log n) as said in editorial? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146256 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146256 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146256\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146269\" commentParentId=\"146256\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146269\" href=\"?#comment-146269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146256\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146269\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We hold two pointers: the first points at the first unread track from the left, and the second points at the first unused head so far. So we take this head and read with its help the maximum number of yet unread tracks (note that they are consequent and begin at the first pointer) according to the best of the two choices described in tutorial. Then we move the first pointer to the first yet unread track, and increment the second by one. Thus each pointer moves <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> times in this iteration of the binary search. Take also in consideration that some heads can be not used at all.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154161\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/s2k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146708/avatar/ec43946f377e5c64.jpg'/> </a>\n <div><a href=\"/profile/s2k\" title=\"Newbie s2k\" class=\"rated-user user-gray\">s2k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154161\" href=\"?#comment-154161\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154161\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146708\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154161\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi. I was just trying to solve problem A of division 2, but was unsuccessful after hours of effort. I eventually lost patience and decided to see the codes of others. I did understand what was going in the code, but couldn't figure out why this method was chosen in the first place. Can someone please help me understand the solution?</p><p>P.S. I'm a newbie with almost no prior knowledge about number theory. :$</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154161 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154161 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154161\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154163\" commentParentId=\"154161\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154163\" href=\"?#comment-154163\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-154161\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154163\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154163\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The number of islands is always one more than the number of splits between two neighboring dominoes. One can easily convince himself by looking at an image in the description.</p><p>There are 4 possibilities of neighboring dominoes:</p> <ul> <li>01 and 01: these attract, so they don't form a split and we don't care about them</li> <li>10 and 10: these attract, so they don't form a split and we don't care about them</li> <li>01 and 10: these don't attract, so they form a split</li> <li>10 and 01: these don't attract, so they form a split</li> </ul><p>So, we can deduce that we're only interested in neighboring dominoes that are different. This means we can just count the number of indexes i (1 <= i < N) such that s[i] != s[i+1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154163 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154163 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154163\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176652\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/S.Ged\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67184/avatar/a38f51555a40b56a.jpg'/> </a>\n <div><a href=\"/profile/S.Ged\" title=\"Candidate Master S.Ged\" class=\"rated-user user-violet\">S.Ged</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 04:10\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176652\" href=\"?#comment-176652\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"176652\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"176652\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"67184\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176652\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm confused by the first sentence of 343A — Rational Resistance tutorial</p><p>How can we obtain a/(a+b) with k+1 resistors if obatined a/b wiht k resistors ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176652 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176652 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176652\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176656\" commentParentId=\"176652\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/afrizal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/103639/avatar/206f6cf479b00060.jpg'/> </a>\n <div><a href=\"/profile/afrizal\" title=\"Expert afrizal\" class=\"rated-user user-blue\">afrizal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 07:05\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176656\" href=\"?#comment-176656\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176652\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"176656\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"103639\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176656\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Remember a/a is 1. If we have a/b resistance, put one more resistor parallel will give <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c1a16b55f7f10840909e0e5863ae3ce22e36c85b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176656 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176656 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176656\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"189636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/namikaze\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/227989/avatar/51e67e9e139a65f2.jpg'/> </a>\n <div><a href=\"/profile/namikaze\" title=\"Unrated, namikaze\" class=\"rated-user user-black\">namikaze</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/28/2014 15:45\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-189636\" href=\"?#comment-189636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"189636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"227989\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-189636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><code>adding one resistor means performing one operation backwards in Euclidean algorithm</code></p><p>Can someone explain this ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-189636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-189636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-189636\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"277029\" commentParentId=\"189636\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TomBombadil\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/106415/avatar/ed9d8ef375273241.jpg'/> </a>\n <div><a href=\"/profile/TomBombadil\" title=\"Specialist TomBombadil\" class=\"rated-user user-cyan\">TomBombadil</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2016 17:50\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-277029\" href=\"?#comment-277029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-189636\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"277029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"106415\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-277029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-orange\" href=\"/profile/gen\" title=\"Master gen\">gen</a> ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-277029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-277029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-277029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"351231\" commentParentId=\"277029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/R.A.X\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/122476/avatar/686763c746ac6e7b.jpg'/> </a>\n <div><a href=\"/profile/R.A.X\" title=\"Specialist R.A.X\" class=\"rated-user user-cyan\">R.A.X</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/27/2017 15:37\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-351231\" href=\"?#comment-351231\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-277029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"351231\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"351231\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"122476\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-351231\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Suppose you have resistance of(17/3), it could be formed by adding 1 + (14/3). If you have resistance of (3/17), it could be obtained by combining resistance of 1 and 3/14 in parallel.</p><p>In terms of variable, a/b could be obtained by 1 + resistors required to create ( a-b)/b resistance, assuming a>b. and a/b if b>a, could be obtained by 1 + resistors required to create ( a/(b-a) ).</p><p>Assuming a>b so resistorRequired(a,b) = 1 + resistorRequired(a-b,b).</p> <pre>resistorReqiored(a-b,b) = 1 + resistorRequired(a-2b,b)</pre><p>............</p> <pre>resistorRequired(a-(q-1)*b ,b) = 1 + resistorRequired(a-q*b,b)</pre><p>let say r = a-q*b == a%b now at this point, one resistance needs to be connected in parallel to the b/r resistance.</p><p>so again problem becomes calculating the requiredResistance(b,r) similar to above problem,</p><p>which is similar to the gcd problem.</p><p>Hope that helps.</p><p>Why it's like gcd(a,b) = gcd(a-b,b) =gcd(a-2b,b) .... </p><p>In case of gcd(a,b) = gcd(a-b,b)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-351231 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-351231 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-351231\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"393063\" commentParentId=\"351231\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ShafinKhadem\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/508696/avatar/1b5c8ae9cf51dc77.jpg'/> </a>\n <div><a href=\"/profile/ShafinKhadem\" title=\"Master ShafinKhadem\" class=\"rated-user user-orange\">ShafinKhadem</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/01/2017 09:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-393063\" href=\"?#comment-393063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-351231\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"393063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"508696\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-393063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for the nice explanation. Now the use of euclidian algorithm to solve this problem makes sense to me.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-393063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-393063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-393063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"220282\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CloverAsta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207753/avatar/45b71a38344fa830.jpg'/> </a>\n <div><a href=\"/profile/CloverAsta\" title=\"Expert CloverAsta\" class=\"rated-user user-blue\">CloverAsta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/01/2015 14:33\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-220282\" href=\"?#comment-220282\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"220282\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207753\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-220282\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain to me the solution for Problem C div2 I understand the transition from <code>k</code> to <code>k + 1</code> but the part about Euclidean algorithm is beyond me</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-220282 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-220282 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-220282\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"232136\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anajin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221428/avatar/b8f5979933e2ce3d.jpg'/> </a>\n <div><a href=\"/profile/anajin\" title=\"Expert anajin\" class=\"rated-user user-blue\">anajin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/03/2015 14:15\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-232136\" href=\"?#comment-232136\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"232136\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-232136\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>water tree can be solved by heavy-light decomposition...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-232136 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-232136 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-232136\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"454886\" commentParentId=\"232136\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cai_lw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/325977/avatar/202b61935928944.jpg'/> </a>\n <div><a href=\"/profile/cai_lw\" title=\"International Master cai_lw\" class=\"rated-user user-orange\">cai_lw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/30/2018 20:04\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-454886\" href=\"?#comment-454886\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-232136\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"454886\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"454886\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"325977\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-454886\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, this is almost the most standard problem for HLD. But their solution is cleverer and has lower time complexity. HLD is a little bit overkill for such simple operations.</p><p>Nevertheless, HLD can pass the test. My HLD solution passed in 900ms.</p><p>Also HLD was a relatively unknown algorithm to the CP community 5 years ago.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-454886 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-454886 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-454886\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"634570\" commentParentId=\"454886\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Suri429\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/776807/avatar/90399ec92a81320a.jpg'/> </a>\n <div><a href=\"/profile/Suri429\" title=\"Master Suri429\" class=\"rated-user user-orange\">Suri429</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2020 08:55\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-634570\" href=\"?#comment-634570\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-454886\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"634570\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"776807\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-634570\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain how to approach this with HLD? I am new to HLD, and not able to get any clue here. </p><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-634570 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-634570 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-634570\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"312598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/29/2016 12:31\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-312598\" href=\"?#comment-312598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"312598\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"312598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-312598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder why I did wrong in the implementation of lazy propagation for Div1D, could anyone kindly lend some help? </p><p><a href=\"//codeforces.com/contest/343/submission/20226349\">http://codeforces.com/contest/343/submission/20226349</a></p><p>Thanks in advance. =)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-312598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-312598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-312598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"357445\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anshulgarg19\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/anshulgarg19\" title=\"Pupil anshulgarg19\" class=\"rated-user user-green\">anshulgarg19</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/02/2017 20:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-357445\" href=\"?#comment-357445\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"357445\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"244328\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-357445\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Accepted solution for the problem 343A Rational Resistance would give 6 as the output for input a = 10 and b = 7 i.e.10/7. But, if we have 5 ohm and 2 ohm resistors in parallel, then we have the same resistance value 10/7. So minimum value should be 2 resistors for this case. Kindly explain if i am wrong in understanding the problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-357445 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-357445 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-357445\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360009\" commentParentId=\"357445\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/snehil10\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/351506/avatar/522f61633a219a3b.jpg'/> </a>\n <div><a href=\"/profile/snehil10\" title=\"Expert snehil10\" class=\"rated-user user-blue\">snehil10</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/14/2017 10:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360009\" href=\"?#comment-360009\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-357445\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"360009\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"351506\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360009\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have only 1-ohm resistors in the beginning. Thus it requires 5 1-ohm resistors to make a 5-ohm resistor, and 2 1-ohm resistors to make a 2-ohm resistor. So according to you answer is 7 and not 2.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360009 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360009 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360009\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371475\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rush_123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/rush_123\" title=\"Expert rush_123\" class=\"rated-user user-blue\">rush_123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/03/2017 17:42\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371475\" href=\"?#comment-371475\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"371475\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"439840\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371475\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 343D — Water Tree query 1 and 2 can be solved using a dfs to find in time and out time for every node and then using segment tree But what about 3rd query how to solve it?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371475 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371475 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371475\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"422269\" commentParentId=\"371475\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stringray\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/575608/avatar/2902babcf56868a2.jpg'/> </a>\n <div><a href=\"/profile/stringray\" title=\"Expert stringray\" class=\"rated-user user-blue\">stringray</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/28/2018 16:13\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-422269\" href=\"?#comment-422269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371475\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"422269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"575608\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-422269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yeah same question .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-422269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-422269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-422269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"437012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ragnarok_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ragnarok_\" title=\"Newbie ragnarok_\" class=\"rated-user user-gray\">ragnarok_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2018 08:59\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-437012\" href=\"?#comment-437012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"437012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"673189\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-437012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Q.343A can anybody explain me why min resistor for 199/200 is 200.....it can be also constructed using 101 resistors(1/2+1/4+1/5+1/40+1/50)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-437012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-437012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-437012\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"573631\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SLIMSHADYNICK\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/598862/avatar/7629f1b29f0fe807.jpg'/> </a>\n <div><a href=\"/profile/SLIMSHADYNICK\" title=\"Candidate Master SLIMSHADYNICK\" class=\"rated-user user-violet\">SLIMSHADYNICK</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2020 21:03\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-573631\" href=\"?#comment-573631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"573631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"598862\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-573631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>correct!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-573631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-573631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-573631\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587715\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pied-piper\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/754580/avatar/a6fb81d49bb96665.jpg'/> </a>\n <div><a href=\"/profile/pied-piper\" title=\"Expert pied-piper\" class=\"rated-user user-blue\">pied-piper</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/11/2020 16:14\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587715\" href=\"?#comment-587715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"587715\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"587715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"754580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It is because they are separate elements and hence they cannot be added together. Only an element and a 1 unit resistance can be added in series(or parallel)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587715\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"791297\" commentParentId=\"587715\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/15/2021 17:25\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-791297\" href=\"?#comment-791297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587715\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"791297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-791297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-791297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-791297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-791297\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"598229\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayank_ag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/644568/avatar/c1136e364e721d18.jpg'/> </a>\n <div><a href=\"/profile/mayank_ag\" title=\"Master mayank_ag\" class=\"rated-user user-orange\">mayank_ag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/05/2020 20:53\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-598229\" href=\"?#comment-598229\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"598229\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"644568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-598229\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>An alternate approach for solving D: Use of lazy segment tree over HLD & Euler path. For every filling, fill Euler path with current query number, and for emptying, fill HLD path from the root with query number. For queries, check which of the seg tree has high query number.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-598229 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-598229 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-598229\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"600816\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Asterix_11\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Asterix_11\" title=\"Pupil Asterix_11\" class=\"rated-user user-green\">Asterix_11</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/11/2020 00:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-600816\" href=\"?#comment-600816\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"600816\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1472760\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-600816\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem 344A</p> <pre><code>#include <iostream>\nusing namespace std;\nint main()\n{\n int a, i, b[100], ans;\n scanf("%d", &a);\n for(i = 0; i < a; ++i){\n scanf("%d", &b[i]);\n }\n ans = 1;\n for(i = 0; i < (a-1); ++i){\n if(b[i] != b[i + 1]){\n ++ans;}\n }\n printf("%d", ans);\n return 0;\n}\n</code></pre><p>This is my code, but I don't know how to improve it, so that the time limit won't be a problem anymore. Any help?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-600816 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-600816 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-600816\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752098\" commentParentId=\"600816\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 09:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752098\" href=\"?#comment-752098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-600816\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can make two variable for prev and current value and if they are not equal you can increment it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752098\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752075\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:25\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752075\" href=\"?#comment-752075\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752075\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752075\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Problem C, if more than one of the elements can be in parallel than for ratio 199 and 200 the answer given is 200. But we may solve this in 74. like 1/2+1/4+1/8+1/10+1/50.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752075 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752075 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752075\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752089\" commentParentId=\"752075\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752089\" href=\"?#comment-752089\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-752075\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752089\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752089\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Okay it would be like either + denominator to the numerator or + numerator to the denominator.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752089 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752089 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752089\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"946539\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mohsina_Shaikh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1396580/avatar/6f21616a2d8d578.jpg'/> </a>\n <div><a href=\"/profile/Mohsina_Shaikh\" title=\"Newbie Mohsina_Shaikh\" class=\"rated-user user-gray\">Mohsina_Shaikh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/24/2022 06:47\">13 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-946539\" href=\"?#comment-946539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"946539\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"946539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1396580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-946539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a> or <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a> or can anyone please explain <code>Alternating Current</code> Solution.Tried so hard but not able to understand it. A</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-946539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-946539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-946539\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"959164\" commentParentId=\"946539\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rishijoshi483\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2453886/avatar/1ecf48b346fe39d0.jpg'/> </a>\n <div><a href=\"/profile/rishijoshi483\" title=\"Expert rishijoshi483\" class=\"rated-user user-blue\">rishijoshi483</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/03/2022 09:44\">12 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-959164\" href=\"?#comment-959164\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-946539\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"959164\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2453886\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-959164\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try it using stack</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-959164 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-959164 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-959164\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"966651\" commentParentId=\"959164\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Yohajji\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2854745/avatar/b31d6e4c63852741.jpg'/> </a>\n <div><a href=\"/profile/Yohajji\" title=\"Newbie Yohajji\" class=\"rated-user user-gray\">Yohajji</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2022 13:35\">11 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-966651\" href=\"?#comment-966651\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-959164\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"966651\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2854745\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-966651\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>using the stack was a brilliant aproach, thank you </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-966651 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-966651 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-966651\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1039007\" commentParentId=\"966651\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AbdelrahmanMahallawy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3189297/avatar/6b2a1658ad37caa0.jpg'/> </a>\n <div><a href=\"/profile/AbdelrahmanMahallawy\" title=\"Newbie AbdelrahmanMahallawy\" class=\"rated-user user-gray\">AbdelrahmanMahallawy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/20/2023 03:36\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1039007\" href=\"?#comment-1039007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-966651\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1039007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3189297\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1039007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>anytime </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1039007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1039007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1039007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8931\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8931 = true;\r\nvar lastPreviewContent8931 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8931] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8931] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:23</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128748fcb8816ab',t:'MTY5NjcwNTk0My4yOTkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1743,"cells":{"problem_id":{"kind":"string","value":"344B"},"contest":{"kind":"string","value":"344"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Simple Molecules"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Simple Molecules</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike is busy carrying out experiments in chemistry. Today he will attempt to join three atoms into one molecule.</p><p>A molecule consists of atoms, with some pairs of atoms connected by atomic bonds. Each atom has a valence number — the number of bonds the atom must form with other atoms. An atom can form <span class=\"tex-font-style-bf\">one or multiple</span> bonds with any other atom, but it cannot form a bond with itself. The number of bonds of an atom in the molecule must be equal to its valence number.</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/067247b5ec73fdf1c952347a64979d80c954606d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>Mike knows valence numbers of the three atoms. Find a molecule that can be built from these atoms according to the stated rules, or determine that it is impossible.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The single line of the input contains three space-separated integers <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span> and <span class=\"tex-span\"><i>c</i></span> (<span class=\"tex-span\">1 ≤ <i>a</i>, <i>b</i>, <i>c</i> ≤ 10<sup class=\"upper-index\">6</sup></span>) — the valence numbers of the given atoms.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If such a molecule can be built, print three space-separated integers — the number of bonds between the 1-st and the 2-nd, the 2-nd and the 3-rd, the 3-rd and the 1-st atoms, correspondingly. If there are multiple solutions, output any of them. If there is no solution, print \"<span class=\"tex-font-style-tt\">Impossible</span>\" (without the quotes).</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1 1 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0 1 1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 4 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 3 2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 1 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Impossible<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The first sample corresponds to the first figure. There are no bonds between atoms 1 and 2 in this case.</p><p>The second sample corresponds to the second figure. There is one or more bonds between each pair of atoms.</p><p>The third sample corresponds to the third figure. There is no solution, because an atom cannot form bonds with itself.</p><p>The configuration in the fourth figure is impossible as each atom must have at least one atomic bond.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"f694548752bf62e8b3720cff400f9179\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"97388d8e9a3336f0fbcbc9a7e735a42b6679436b\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='f694548752bf62e8b3720cff400f9179'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F344%2Fproblem%2FB%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='f694548752bf62e8b3720cff400f9179'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/344\">Codeforces Round 200 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='f694548752bf62e8b3720cff400f9179'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/344/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Brute force\">\r\n brute force\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Graphs\">\r\n graphs\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1200\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='f694548752bf62e8b3720cff400f9179'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3463\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='f694548752bf62e8b3720cff400f9179'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3463\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8851\" title=\"Codeforces Round #200\" target=\"_blank\">Codeforces Round #200</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1854:1855\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8860\" title=\"Codeforces Round #200 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1850:1851\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/344\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/344/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/344/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/344/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/344/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/344/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/344/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/344/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_f824d916d59d33d736378e3ccec4d46e775ecdd4\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Simple Molecules</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike is busy carrying out experiments in chemistry. Today he will attempt to join three atoms into one molecule.</p><p>A molecule consists of atoms, with some pairs of atoms connected by atomic bonds. Each atom has a valence number — the number of bonds the atom must form with other atoms. An atom can form <span class=\"tex-font-style-bf\">one or multiple</span> bonds with any other atom, but it cannot form a bond with itself. The number of bonds of an atom in the molecule must be equal to its valence number.</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/067247b5ec73fdf1c952347a64979d80c954606d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>Mike knows valence numbers of the three atoms. Find a molecule that can be built from these atoms according to the stated rules, or determine that it is impossible.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The single line of the input contains three space-separated integers <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span> and <span class=\"tex-span\"><i>c</i></span> (<span class=\"tex-span\">1 ≤ <i>a</i>, <i>b</i>, <i>c</i> ≤ 10<sup class=\"upper-index\">6</sup></span>) — the valence numbers of the given atoms.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If such a molecule can be built, print three space-separated integers — the number of bonds between the 1-st and the 2-nd, the 2-nd and the 3-rd, the 3-rd and the 1-st atoms, correspondingly. If there are multiple solutions, output any of them. If there is no solution, print "<span class=\"tex-font-style-tt\">Impossible</span>" (without the quotes).</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1 1 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0 1 1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 4 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 3 2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 1 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Impossible<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The first sample corresponds to the first figure. There are no bonds between atoms 1 and 2 in this case.</p><p>The second sample corresponds to the second figure. There is one or more bonds between each pair of atoms.</p><p>The third sample corresponds to the third figure. There is no solution, because an atom cannot form bonds with itself.</p><p>The configuration in the fourth figure is impossible as each atom must have at least one atomic bond.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:41</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bda20bd616ab',t:'MTY5NjY0NjAyMS41NDIwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Brute force\", \"Graphs\", \"Mathematics including integration, differential equations, etc\"]"},"short_tags":{"kind":"string","value":"[\"brute force\", \"graphs\", \"math\", \"*1200\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8860"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"21ba25574a0615e5dc71db6e32a512d8\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #200 Tutorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #200 Tutorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='21ba25574a0615e5dc71db6e32a512d8'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8860\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/gen\">gen</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gen\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gen\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gen\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gen\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gen\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gen\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gen\" style=\"text-decoration:none;color:black !important;\">gen's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8915\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8860\"> <p>Codeforces Round #200 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a>,\r\n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h4><a href=\"/contest/344/problem/A\" title=\"Codeforces Round 200 (Div. 2)\">344A - Magnets</a></h4><p>By the definition each block consists of a number of consequent and equally oriented dominoes. That means that in places where adjacent dominoes are not oriented equally, one block ends and another block starts. So, if there are <span class=\"tex-span\"><i>x</i></span> such places, the answer is equal to <span class=\"tex-span\"><i>x</i> + 1</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> The problem was created a day before the contest and filled in the last part of a physically flavoured DivII complect. :]</p><h4><a href=\"/contest/344/problem/B\" title=\"Codeforces Round 200 (Div. 2)\">344B - Simple Molecules</a></h4><p>First solution. First, the sum <span class=\"tex-span\"><i>a</i> + <i>b</i> + <i>c</i></span> should be even, since each bond adds 2 to the sum. Now let <span class=\"tex-span\"><i>x</i></span>, <span class=\"tex-span\"><i>y</i></span>, <span class=\"tex-span\"><i>z</i></span> be the number of bonds between 1st and 2nd, 2nd and 3rd, 3rd and 1st atoms, accordingly. So we have to solve the system <span class=\"tex-span\"><i>x</i> + <i>z</i> = <i>a</i></span>, <span class=\"tex-span\"><i>y</i> + <i>x</i> = <i>b</i></span>, <span class=\"tex-span\"><i>z</i> + <i>y</i> = <i>c</i></span>. Now observe that the solution to the system is the length of the tangents on the triangle with sides of length <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span> to its inscribed circle, and are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/2cee22ffa44dda3ce1b315e8cceef38c6288cf2c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1aed1c363b13d01e1b412b9cd3d5e34d19eb9c96.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/30fbfc651674588cadbee1fedd1e4b0d08d1ad4e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. If the problem asked only the possibility of building such a molecule, we could just check if there exists (possibly degenerate) triangle with sides <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span>.</p><p><img alt=\" \" src=\"/predownloaded/e3/d3/e3d3c930f4f93ca68c1e61630a2771472ecbd60a.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Second solution. Bruteforce all <span class=\"tex-span\"><i>x</i></span> values. For a fixed <span class=\"tex-span\"><i>x</i></span> values of <span class=\"tex-span\"><i>y</i></span> and <span class=\"tex-span\"><i>z</i></span> are defined uniquely: <span class=\"tex-span\"><i>y</i> = <i>b</i> - <i>x</i></span>, <span class=\"tex-span\"><i>z</i> = <i>a</i> - <i>x</i></span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(1) / <i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> Can you solve the problem for any vertex number <span class=\"tex-span\"><i>n</i></span>? When and how can such a graph be built?</p><h4><a href=\"/contest/343/problem/A\" title=\"Codeforces Round 200 (Div. 1)\">343A - Rational Resistance</a></h4><p>If a fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> can be obtained with <span class=\"tex-span\"><i>k</i></span> resistors, then it is simple to calculate that we can obtain fractions <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b6913fd8136f518e8a7898a9b759b74c4d483101.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/daf9572f0aa7677d7961c329e6277818df63bd9f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> with <span class=\"tex-span\"><i>k</i> + 1</span> resistors. So adding one resistor means performing one operation backwards in Euclidean algorithm. That means that the answer is equal to the number of steps in standard Euclidean algorithm.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e847ae811adbd761fa24db4ba7a6827e0806d670.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Бонус:</strong> At first we thought about the major problem (any two elements can be joined), but had a moment of eureka and got that the given problem unexpectedly naturally can be reduced to GCD. By the way, the result tree — <a href=\"https://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree\">http://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree</a>.</p><h4><a href=\"/contest/343/problem/B\" title=\"Codeforces Round 200 (Div. 1)\">343B - Alternating Current</a></h4><p>Let us solve the following problem first: we are given a string of symbols A and B. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>A</i></span>, then at the <span class=\"tex-span\"><i>i</i></span>-th step the upper wire (see figure) is being put over the lower wire. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>B</i></span>, the lower wire is being put over the upper wire at <span class=\"tex-span\"><i>i</i></span>-th step. Observe that if some two symbols <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are adjacent, we can untangle this place, throw the symbols out and obtain the string of length two symbols less. So the wires can be untangled iff the number of A's and B's in the string is the same. The given problem can be reduced to the described in a following fashion: in each odd position we change – to B and + to A. In each even position we change — to A and + to B. The reduction is correct, since on each even position the order of — and + are always swapped, and in each odd position their order is the same as in the beginning.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> If you are interested by this problem, you can learn about the braid theory <a href=\"https://en.wikipedia.org/wiki/Braid_theory\">http://en.wikipedia.org/wiki/Braid_theory</a> :] Fun fact: a harder version of this problem was planned already for Round #142, but the error in solution idea was found, and the problem was left to lay for almost a year.</p><h4><a href=\"/contest/343/problem/C\" title=\"Codeforces Round 200 (Div. 1)\">343C - Read Time</a></h4><p>Let's search the answer <span class=\"tex-span\"><i>t</i></span> with the binary search. Fix some value of <span class=\"tex-span\"><i>t</i></span>. Look at the first head from the left <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> that can read track <span class=\"tex-span\"><i>p</i>[0]</span>. If <span class=\"tex-span\"><i>p</i>[0] > <i>h</i>[<i>i</i>]</span>, then <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> goes to the right <span class=\"tex-span\"><i>t</i></span> seconds and reads all tracks on its way. Otherwise if <span class=\"tex-span\"><i>p</i>[0] ≤ <i>h</i>[<i>i</i>]</span>, then the head has two choices:</p> <ol> <li>go to the right <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> seconds, then <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> to the left and <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> again to the left;</li> <li>go to the left <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> seconds, then <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> to the right and <span class=\"tex-span\"><i>t</i> - 2·(<i>h</i>[<i>i</i>] - <i>p</i>[0])</span> again to the right.</li> </ol><p>Obviously, for <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> it is more advantageous to visit the track positioned as much as possible to the right. So we choose by <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7edc4f5554e1d173945160b7deaca92e61d7a755.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Then we move the pointer onto the first unread track, and repeat the algorithm for <span class=\"tex-span\"><i>h</i>[<i>i</i> + 1]</span>, and so on with each head.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/3342f24e1fd6ab939313f6d6278245c95d89544f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a>.</p><p><strong>Bonus:</strong> The problem is completely real, if the disk has only a single head, if we know, what tracks should be read; then the optimal algorithm chooses between the two choices described above. I and <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a> were listening this on a lecture, and created the given problem out of boredom ;]</p><h4><a href=\"/contest/343/problem/D\" title=\"Codeforces Round 200 (Div. 1)\">343D - Water Tree</a></h4><p>Let's learn how to color a whole subtree. For that enumerate all vertices in post-order DFS. Then each subtree covers a single continious vertex number segment. For each vertex we store the bounds of such segment for a subtree with a root in this vertex. Then to color a subtree means to color a segment in a segment tree.</p><p>Then create a segment tree that has a following property: if a vertex <span class=\"tex-span\"><i>v</i></span> was emptied, and is still empty, then this vertex is colored in the segment tree. In the beginning "empty" all the vertices. That is, color all the vertices in the segment tree. With this tree we can efficiently process the queries:</p> <ol> <li><p>Fill a vertex <span class=\"tex-span\"><i>v</i></span>. Clean the interval for the subtree of <span class=\"tex-span\"><i>v</i></span>. If before that some vertex of a subtree was empty, color the parent of <span class=\"tex-span\"><i>v</i></span>.</p></li> <li><p>Empty a vertex <span class=\"tex-span\"><i>v</i></span>. Color the vertex <span class=\"tex-span\"><i>v</i></span> in the segment tree.</p></li> <li><p>Reply whether a vertex <span class=\"tex-span\"><i>v</i></span> is filled. If in the segment tree at least one vertex is colored, then there is such a descendant of <span class=\"tex-span\"><i>v</i></span> that is empty now, so the vertex <span class=\"tex-span\"><i>v</i></span> is not filled.</p></li> </ol><p><a class=\"rated-user user-blue\" href=\"/profile/Shtrix\" title=\"Expert Shtrix\">Shtrix</a> noted that essentially the same solution can be implemented with only a single set.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fcb5cb34164112e0db4b3ef4b921f55df7ffb005.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> Some participants could see the similarities with a problem Ball Machine from BOI 2013, but the solutions to the both problems are quite different.</p><h4><a href=\"/contest/343/problem/E\" title=\"Codeforces Round 200 (Div. 1)\">343E - Pumping Stations</a></h4><p>In this problem we are asked to find such graph vertex permutation that maximizes the sum of the maximum flows sent between each two consequtive vertices in the permutation.</p><p>The problem can be solved with <a href=\"https://en.wikipedia.org/wiki/Gomory%E2%80%93Hu_tree\">Gomory-Hu</a> tree data structure. For a given weighted graph the tree has the following properties:</p> <ol> <li>The vertex set of the tree and the graph is the same.</li> <li>The maximum flow between vertices <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> in the tree is equal to the maximum flow in the graph.</li> </ol><p>Surprisingly, such a tree exists for any weighted graph, and can be built in <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. It appears that the answer to the problem is equal to the sum of the edge weights in this tree.</p><p>We prove this statement by induction on the number of the tree vertices. Pick the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> with the smallest weight in the tree. Consider that in an optimal permutation more than one path between two adjacent verteces in the permutation passes through this edge. Erase all these paths, then each of the <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> subtrees holds a set of disjoint remaining paths from the permutation. For each set, join all the paths in one chain, obtaining two chains. These chains we join by a path <span class=\"tex-span\"><i>s</i></span> that goes trough the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>. Thus we have built a permutation that is not worse than the considered one. For a path <span class=\"tex-span\"><i>s</i></span> the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> is the smallest, so the flow along this path is equal to the weight of this edge. It follows from the induction that in subtrees <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> the answer is equal to the sum of edges. By adding the weight of edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>, we get the desired result.</p><p>From the last paragraph it is clear how to build such a permutation: take the smallest edge, obtain two chains from the vertex subtrees recursively, and add them together to form a one chain. Since there are not many vertices, we can do this part in <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-orange\" href=\"/profile/Gerald\" title=\"Master Gerald\">Gerald</a>.</p><p><strong>Bonus:</strong> Shortly before the contest we decided to make the constraints more loyal, so some solution that find Gomory-Hu tree by finding flow <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> times also passed. We hope that nobody is particularly saddened by this fact. (;</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/343\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/344\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-8915\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"8860\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=200\" class=\"tag notice\" style=\"text-decoration: none;\">200</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+64</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8860#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8860#comments\">\n 53\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8931\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (43)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145823\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bipinb1994\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/91315/avatar/b4e2d8ac5b2569a3.jpg'/> </a>\n <div><a href=\"/profile/bipinb1994\" title=\"Expert bipinb1994\" class=\"rated-user user-blue\">bipinb1994</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 07:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145823\" href=\"?#comment-145823\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145823\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-15\"\r\n data-commentUserId=\"91315\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145823\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hai this was my first round in Codeforces. But my code was not accepted and it says that it was wrong with the 3rd test case. What i did was put a loop from 0 to n-1 and i checked ch[i][!=ch[i+1][0] then count++; else continue where 'ch' is the character array(2-D) whose size was Nx3 ...Is this algorithm completely wrong. As i said this was the first round here i did not understand what is wrong with this. If possible please do tell me what is wrong with this algorithm..:(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145823 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145823 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145823\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145863\" commentParentId=\"145823\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 14:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145863\" href=\"?#comment-145863\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145823\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145863\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145863\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please look at link <a href=\"//codeforces.com/contest/344/submission/4461494\">http://codeforces.com/contest/344/submission/4461494</a>. </p><p>The log says</p><p>Time: 0 ms, memory: 0 KB Verdict: WRONG_ANSWER Input 1 10 Output 0 Answer 1 Checker comment wrong answer 1st numbers differ — expected: '1', found: '0'</p><p>I believe this should be self explanatory. </p><p>Also it would help playing around with the system before trying to enter a rated match.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145863 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145863 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145863\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146026\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ka16\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ka16\" title=\"Pupil ka16\" class=\"rated-user user-green\">ka16</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 06:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146026\" href=\"?#comment-146026\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146026\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"12131\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146026\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody please clarify the two choices of head(s) in the solution of 343C-Read Time problem above? I couldn't understand it completely. Thank in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146026 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146026 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146026\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146037\" commentParentId=\"146026\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hriss95\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27396/avatar/d6cec8eac7bdbde3.jpg'/> </a>\n <div><a href=\"/profile/hriss95\" title=\"Expert hriss95\" class=\"rated-user user-blue\">hriss95</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 13:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146037\" href=\"?#comment-146037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146026\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146037\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"27396\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have to choose one of the two types moving: first to the right or first to the left. You have to use the one which covers more points to the right. Note that both types of moving cover the left point and that's why you have to take as much as points as you can to the right.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146037\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sorin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/sorin\" title=\"Expert sorin\" class=\"rated-user user-blue\">sorin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 12:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146034\" href=\"?#comment-146034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"124904\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody give me a hint for the bonus at Div2 — B? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146034\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146064\" commentParentId=\"146034\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 21:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146064\" href=\"?#comment-146064\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146034\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146064\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146064\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Think greedy ;]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146064 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146064 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146064\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"152157\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ghooo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2010/avatar/659a8aca8b12506a.jpg'/> </a>\n <div><a href=\"/profile/ghooo\" title=\"Master ghooo\" class=\"rated-user user-orange\">ghooo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/26/2013 08:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-152157\" href=\"?#comment-152157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"152157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2010\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-152157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>will the connections between the atoms be circular? like 1 <-> 2 <-> 3 <-> 4 <-> 5 ... n <-> 1 (again) ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-152157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-152157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-152157\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"521750\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/n0tred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1177564/avatar/a46e0281e87dd6c9.jpg'/> </a>\n <div><a href=\"/profile/n0tred\" title=\"Candidate Master n0tred\" class=\"rated-user user-violet\">n0tred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/25/2019 14:29\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-521750\" href=\"?#comment-521750\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"521750\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1177564\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-521750\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you give a better hint? (Maybe through a spoiler, I suppose)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-521750 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-521750 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-521750\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"523308\" commentParentId=\"521750\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/29/2019 09:36\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-523308\" href=\"?#comment-523308\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-521750\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"523308\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-523308\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the algorithm that continuously connects the vertex with the smallest degree with the vertex with the largest degree works (here by degree I mean the unconnected edges), and builds a connected graph. I think this can be proved by induction.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-523308 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-523308 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-523308\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146129\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 11:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146129\" href=\"?#comment-146129\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146129\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146129\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think there is an issue with Problem 343A — Rational Resistance. Here according to the editorial the answer to the ratio 6/5 would be 6(I have verified this with an accepted solution). But this ratio can be achieved with a resistance of 2 and 3 in parallel, which makes the number of resistors required equal to 5 which would imply the editorial and the system tests to be wrong.</p><p>Am I missing something here?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146129 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146129 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146129\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146259\" commentParentId=\"146129\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146259\" href=\"?#comment-146259\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146129\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146259\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146259\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think it's because the definition of <strong>one element</strong> only let you add <strong>one</strong> new unit resistor to another element</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146259 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146259 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146259\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146256\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146256\" href=\"?#comment-146256\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146256\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146256\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for the nice problems!</p><p>I just have a little question on 343C — Read Time. I use the same algorithm and get AC, but my algorithm is running at O(n log^2 n)... as for the step: "Then we move the pointer onto the first unread track" I use another binary search...</p><p>how can I implement the same algorithm with O(n log n) as said in editorial? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146256 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146256 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146256\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146269\" commentParentId=\"146256\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146269\" href=\"?#comment-146269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146256\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146269\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We hold two pointers: the first points at the first unread track from the left, and the second points at the first unused head so far. So we take this head and read with its help the maximum number of yet unread tracks (note that they are consequent and begin at the first pointer) according to the best of the two choices described in tutorial. Then we move the first pointer to the first yet unread track, and increment the second by one. Thus each pointer moves <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> times in this iteration of the binary search. Take also in consideration that some heads can be not used at all.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154161\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/s2k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146708/avatar/ec43946f377e5c64.jpg'/> </a>\n <div><a href=\"/profile/s2k\" title=\"Newbie s2k\" class=\"rated-user user-gray\">s2k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154161\" href=\"?#comment-154161\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154161\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146708\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154161\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi. I was just trying to solve problem A of division 2, but was unsuccessful after hours of effort. I eventually lost patience and decided to see the codes of others. I did understand what was going in the code, but couldn't figure out why this method was chosen in the first place. Can someone please help me understand the solution?</p><p>P.S. I'm a newbie with almost no prior knowledge about number theory. :$</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154161 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154161 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154161\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154163\" commentParentId=\"154161\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154163\" href=\"?#comment-154163\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-154161\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154163\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154163\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The number of islands is always one more than the number of splits between two neighboring dominoes. One can easily convince himself by looking at an image in the description.</p><p>There are 4 possibilities of neighboring dominoes:</p> <ul> <li>01 and 01: these attract, so they don't form a split and we don't care about them</li> <li>10 and 10: these attract, so they don't form a split and we don't care about them</li> <li>01 and 10: these don't attract, so they form a split</li> <li>10 and 01: these don't attract, so they form a split</li> </ul><p>So, we can deduce that we're only interested in neighboring dominoes that are different. This means we can just count the number of indexes i (1 <= i < N) such that s[i] != s[i+1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154163 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154163 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154163\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176652\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/S.Ged\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67184/avatar/a38f51555a40b56a.jpg'/> </a>\n <div><a href=\"/profile/S.Ged\" title=\"Candidate Master S.Ged\" class=\"rated-user user-violet\">S.Ged</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 04:10\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176652\" href=\"?#comment-176652\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"176652\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"176652\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"67184\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176652\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm confused by the first sentence of 343A — Rational Resistance tutorial</p><p>How can we obtain a/(a+b) with k+1 resistors if obatined a/b wiht k resistors ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176652 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176652 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176652\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176656\" commentParentId=\"176652\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/afrizal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/103639/avatar/206f6cf479b00060.jpg'/> </a>\n <div><a href=\"/profile/afrizal\" title=\"Expert afrizal\" class=\"rated-user user-blue\">afrizal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 07:05\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176656\" href=\"?#comment-176656\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176652\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"176656\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"103639\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176656\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Remember a/a is 1. If we have a/b resistance, put one more resistor parallel will give <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c1a16b55f7f10840909e0e5863ae3ce22e36c85b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176656 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176656 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176656\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"189636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/namikaze\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/227989/avatar/51e67e9e139a65f2.jpg'/> </a>\n <div><a href=\"/profile/namikaze\" title=\"Unrated, namikaze\" class=\"rated-user user-black\">namikaze</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/28/2014 15:45\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-189636\" href=\"?#comment-189636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"189636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"227989\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-189636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><code>adding one resistor means performing one operation backwards in Euclidean algorithm</code></p><p>Can someone explain this ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-189636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-189636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-189636\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"277029\" commentParentId=\"189636\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TomBombadil\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/106415/avatar/ed9d8ef375273241.jpg'/> </a>\n <div><a href=\"/profile/TomBombadil\" title=\"Specialist TomBombadil\" class=\"rated-user user-cyan\">TomBombadil</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2016 17:50\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-277029\" href=\"?#comment-277029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-189636\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"277029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"106415\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-277029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-orange\" href=\"/profile/gen\" title=\"Master gen\">gen</a> ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-277029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-277029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-277029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"351231\" commentParentId=\"277029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/R.A.X\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/122476/avatar/686763c746ac6e7b.jpg'/> </a>\n <div><a href=\"/profile/R.A.X\" title=\"Specialist R.A.X\" class=\"rated-user user-cyan\">R.A.X</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/27/2017 15:37\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-351231\" href=\"?#comment-351231\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-277029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"351231\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"351231\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"122476\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-351231\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Suppose you have resistance of(17/3), it could be formed by adding 1 + (14/3). If you have resistance of (3/17), it could be obtained by combining resistance of 1 and 3/14 in parallel.</p><p>In terms of variable, a/b could be obtained by 1 + resistors required to create ( a-b)/b resistance, assuming a>b. and a/b if b>a, could be obtained by 1 + resistors required to create ( a/(b-a) ).</p><p>Assuming a>b so resistorRequired(a,b) = 1 + resistorRequired(a-b,b).</p> <pre>resistorReqiored(a-b,b) = 1 + resistorRequired(a-2b,b)</pre><p>............</p> <pre>resistorRequired(a-(q-1)*b ,b) = 1 + resistorRequired(a-q*b,b)</pre><p>let say r = a-q*b == a%b now at this point, one resistance needs to be connected in parallel to the b/r resistance.</p><p>so again problem becomes calculating the requiredResistance(b,r) similar to above problem,</p><p>which is similar to the gcd problem.</p><p>Hope that helps.</p><p>Why it's like gcd(a,b) = gcd(a-b,b) =gcd(a-2b,b) .... </p><p>In case of gcd(a,b) = gcd(a-b,b)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-351231 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-351231 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-351231\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"393063\" commentParentId=\"351231\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ShafinKhadem\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/508696/avatar/1b5c8ae9cf51dc77.jpg'/> </a>\n <div><a href=\"/profile/ShafinKhadem\" title=\"Master ShafinKhadem\" class=\"rated-user user-orange\">ShafinKhadem</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/01/2017 09:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-393063\" href=\"?#comment-393063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-351231\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"393063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"508696\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-393063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for the nice explanation. Now the use of euclidian algorithm to solve this problem makes sense to me.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-393063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-393063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-393063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"220282\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CloverAsta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207753/avatar/45b71a38344fa830.jpg'/> </a>\n <div><a href=\"/profile/CloverAsta\" title=\"Expert CloverAsta\" class=\"rated-user user-blue\">CloverAsta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/01/2015 14:33\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-220282\" href=\"?#comment-220282\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"220282\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207753\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-220282\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain to me the solution for Problem C div2 I understand the transition from <code>k</code> to <code>k + 1</code> but the part about Euclidean algorithm is beyond me</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-220282 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-220282 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-220282\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"232136\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anajin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221428/avatar/b8f5979933e2ce3d.jpg'/> </a>\n <div><a href=\"/profile/anajin\" title=\"Expert anajin\" class=\"rated-user user-blue\">anajin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/03/2015 14:15\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-232136\" href=\"?#comment-232136\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"232136\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-232136\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>water tree can be solved by heavy-light decomposition...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-232136 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-232136 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-232136\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"454886\" commentParentId=\"232136\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cai_lw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/325977/avatar/202b61935928944.jpg'/> </a>\n <div><a href=\"/profile/cai_lw\" title=\"International Master cai_lw\" class=\"rated-user user-orange\">cai_lw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/30/2018 20:04\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-454886\" href=\"?#comment-454886\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-232136\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"454886\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"454886\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"325977\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-454886\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, this is almost the most standard problem for HLD. But their solution is cleverer and has lower time complexity. HLD is a little bit overkill for such simple operations.</p><p>Nevertheless, HLD can pass the test. My HLD solution passed in 900ms.</p><p>Also HLD was a relatively unknown algorithm to the CP community 5 years ago.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-454886 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-454886 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-454886\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"634570\" commentParentId=\"454886\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Suri429\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/776807/avatar/90399ec92a81320a.jpg'/> </a>\n <div><a href=\"/profile/Suri429\" title=\"Master Suri429\" class=\"rated-user user-orange\">Suri429</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2020 08:55\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-634570\" href=\"?#comment-634570\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-454886\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"634570\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"776807\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-634570\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain how to approach this with HLD? I am new to HLD, and not able to get any clue here. </p><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-634570 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-634570 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-634570\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"312598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/29/2016 12:31\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-312598\" href=\"?#comment-312598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"312598\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"312598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-312598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder why I did wrong in the implementation of lazy propagation for Div1D, could anyone kindly lend some help? </p><p><a href=\"//codeforces.com/contest/343/submission/20226349\">http://codeforces.com/contest/343/submission/20226349</a></p><p>Thanks in advance. =)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-312598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-312598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-312598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"357445\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anshulgarg19\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/anshulgarg19\" title=\"Pupil anshulgarg19\" class=\"rated-user user-green\">anshulgarg19</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/02/2017 20:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-357445\" href=\"?#comment-357445\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"357445\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"244328\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-357445\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Accepted solution for the problem 343A Rational Resistance would give 6 as the output for input a = 10 and b = 7 i.e.10/7. But, if we have 5 ohm and 2 ohm resistors in parallel, then we have the same resistance value 10/7. So minimum value should be 2 resistors for this case. Kindly explain if i am wrong in understanding the problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-357445 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-357445 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-357445\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360009\" commentParentId=\"357445\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/snehil10\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/351506/avatar/522f61633a219a3b.jpg'/> </a>\n <div><a href=\"/profile/snehil10\" title=\"Expert snehil10\" class=\"rated-user user-blue\">snehil10</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/14/2017 10:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360009\" href=\"?#comment-360009\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-357445\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"360009\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"351506\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360009\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have only 1-ohm resistors in the beginning. Thus it requires 5 1-ohm resistors to make a 5-ohm resistor, and 2 1-ohm resistors to make a 2-ohm resistor. So according to you answer is 7 and not 2.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360009 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360009 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360009\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371475\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rush_123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/rush_123\" title=\"Expert rush_123\" class=\"rated-user user-blue\">rush_123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/03/2017 17:42\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371475\" href=\"?#comment-371475\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"371475\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"439840\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371475\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 343D — Water Tree query 1 and 2 can be solved using a dfs to find in time and out time for every node and then using segment tree But what about 3rd query how to solve it?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371475 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371475 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371475\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"422269\" commentParentId=\"371475\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stringray\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/575608/avatar/2902babcf56868a2.jpg'/> </a>\n <div><a href=\"/profile/stringray\" title=\"Expert stringray\" class=\"rated-user user-blue\">stringray</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/28/2018 16:13\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-422269\" href=\"?#comment-422269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371475\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"422269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"575608\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-422269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yeah same question .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-422269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-422269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-422269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"437012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ragnarok_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ragnarok_\" title=\"Newbie ragnarok_\" class=\"rated-user user-gray\">ragnarok_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2018 08:59\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-437012\" href=\"?#comment-437012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"437012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"673189\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-437012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Q.343A can anybody explain me why min resistor for 199/200 is 200.....it can be also constructed using 101 resistors(1/2+1/4+1/5+1/40+1/50)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-437012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-437012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-437012\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"573631\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SLIMSHADYNICK\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/598862/avatar/7629f1b29f0fe807.jpg'/> </a>\n <div><a href=\"/profile/SLIMSHADYNICK\" title=\"Candidate Master SLIMSHADYNICK\" class=\"rated-user user-violet\">SLIMSHADYNICK</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2020 21:03\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-573631\" href=\"?#comment-573631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"573631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"598862\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-573631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>correct!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-573631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-573631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-573631\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587715\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pied-piper\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/754580/avatar/a6fb81d49bb96665.jpg'/> </a>\n <div><a href=\"/profile/pied-piper\" title=\"Expert pied-piper\" class=\"rated-user user-blue\">pied-piper</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/11/2020 16:14\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587715\" href=\"?#comment-587715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"587715\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"587715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"754580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It is because they are separate elements and hence they cannot be added together. Only an element and a 1 unit resistance can be added in series(or parallel)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587715\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"791297\" commentParentId=\"587715\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/15/2021 17:25\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-791297\" href=\"?#comment-791297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587715\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"791297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-791297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-791297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-791297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-791297\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"598229\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayank_ag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/644568/avatar/c1136e364e721d18.jpg'/> </a>\n <div><a href=\"/profile/mayank_ag\" title=\"Master mayank_ag\" class=\"rated-user user-orange\">mayank_ag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/05/2020 20:53\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-598229\" href=\"?#comment-598229\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"598229\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"644568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-598229\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>An alternate approach for solving D: Use of lazy segment tree over HLD & Euler path. For every filling, fill Euler path with current query number, and for emptying, fill HLD path from the root with query number. For queries, check which of the seg tree has high query number.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-598229 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-598229 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-598229\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"600816\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Asterix_11\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Asterix_11\" title=\"Pupil Asterix_11\" class=\"rated-user user-green\">Asterix_11</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/11/2020 00:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-600816\" href=\"?#comment-600816\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"600816\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1472760\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-600816\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem 344A</p> <pre><code>#include <iostream>\nusing namespace std;\nint main()\n{\n int a, i, b[100], ans;\n scanf("%d", &a);\n for(i = 0; i < a; ++i){\n scanf("%d", &b[i]);\n }\n ans = 1;\n for(i = 0; i < (a-1); ++i){\n if(b[i] != b[i + 1]){\n ++ans;}\n }\n printf("%d", ans);\n return 0;\n}\n</code></pre><p>This is my code, but I don't know how to improve it, so that the time limit won't be a problem anymore. Any help?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-600816 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-600816 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-600816\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752098\" commentParentId=\"600816\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 09:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752098\" href=\"?#comment-752098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-600816\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can make two variable for prev and current value and if they are not equal you can increment it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752098\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752075\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:25\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752075\" href=\"?#comment-752075\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752075\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752075\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Problem C, if more than one of the elements can be in parallel than for ratio 199 and 200 the answer given is 200. But we may solve this in 74. like 1/2+1/4+1/8+1/10+1/50.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752075 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752075 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752075\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752089\" commentParentId=\"752075\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752089\" href=\"?#comment-752089\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-752075\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752089\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752089\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Okay it would be like either + denominator to the numerator or + numerator to the denominator.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752089 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752089 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752089\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"946539\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mohsina_Shaikh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1396580/avatar/6f21616a2d8d578.jpg'/> </a>\n <div><a href=\"/profile/Mohsina_Shaikh\" title=\"Newbie Mohsina_Shaikh\" class=\"rated-user user-gray\">Mohsina_Shaikh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/24/2022 06:47\">13 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-946539\" href=\"?#comment-946539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"946539\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"946539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1396580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-946539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a> or <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a> or can anyone please explain <code>Alternating Current</code> Solution.Tried so hard but not able to understand it. A</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-946539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-946539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-946539\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"959164\" commentParentId=\"946539\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rishijoshi483\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2453886/avatar/1ecf48b346fe39d0.jpg'/> </a>\n <div><a href=\"/profile/rishijoshi483\" title=\"Expert rishijoshi483\" class=\"rated-user user-blue\">rishijoshi483</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/03/2022 09:44\">12 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-959164\" href=\"?#comment-959164\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-946539\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"959164\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2453886\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-959164\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try it using stack</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-959164 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-959164 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-959164\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"966651\" commentParentId=\"959164\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Yohajji\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2854745/avatar/b31d6e4c63852741.jpg'/> </a>\n <div><a href=\"/profile/Yohajji\" title=\"Newbie Yohajji\" class=\"rated-user user-gray\">Yohajji</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2022 13:35\">11 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-966651\" href=\"?#comment-966651\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-959164\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"966651\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2854745\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-966651\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>using the stack was a brilliant aproach, thank you </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-966651 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-966651 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-966651\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1039007\" commentParentId=\"966651\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AbdelrahmanMahallawy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3189297/avatar/6b2a1658ad37caa0.jpg'/> </a>\n <div><a href=\"/profile/AbdelrahmanMahallawy\" title=\"Newbie AbdelrahmanMahallawy\" class=\"rated-user user-gray\">AbdelrahmanMahallawy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/20/2023 03:36\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1039007\" href=\"?#comment-1039007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-966651\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1039007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3189297\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1039007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>anytime </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1039007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1039007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1039007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8931\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8931 = true;\r\nvar lastPreviewContent8931 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8931] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8931] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:23</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128748fcb8816ab',t:'MTY5NjcwNTk0My4yOTkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1744,"cells":{"problem_id":{"kind":"string","value":"344C"},"contest":{"kind":"string","value":"344"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Rational Resistance"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Rational Resistance</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike is building a time machine in his spare time. To finish the work, he needs a resistor with a certain resistance value.</p><p>However, all Mike has is lots of identical resistors with unit resistance <span class=\"tex-span\"><i>R</i><sub class=\"lower-index\">0</sub> = 1</span>. Elements with other resistance can be constructed from these resistors. In this problem, we will consider the following as elements: </p><ol> <li> one resistor; </li><li> an element and <span class=\"tex-font-style-bf\">one</span> resistor plugged in sequence; </li><li> an element and <span class=\"tex-font-style-bf\">one</span> resistor plugged in parallel. </li></ol><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/fc5dca8df3a2578a728607daccf946b754d1cd00.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>With the consecutive connection the resistance of the new element equals <span class=\"tex-span\"><i>R</i> = <i>R</i><sub class=\"lower-index\"><i>e</i></sub> + <i>R</i><sub class=\"lower-index\">0</sub></span>. With the parallel connection the resistance of the new element equals <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/8e69f2f9d85e6584607971a68a207b22774fdf76.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>. In this case <span class=\"tex-span\"><i>R</i><sub class=\"lower-index\"><i>e</i></sub></span> equals the resistance of the element being connected.</p><p>Mike needs to assemble an element with a resistance equal to the fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>. Determine the smallest possible number of resistors he needs to make such an element.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The single input line contains two space-separated integers <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span> (<span class=\"tex-span\">1 ≤ <i>a</i>, <i>b</i> ≤ 10<sup class=\"upper-index\">18</sup></span>). It is guaranteed that the fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> is irreducible. It is guaranteed that a solution always exists.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single number — the answer to the problem.</p><p>Please do not use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in С++. It is recommended to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>199 200<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>200<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample, one resistor is enough.</p><p>In the second sample one can connect the resistors in parallel, take the resulting element and connect it to a third resistor consecutively. Then, we get an element with resistance <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5305da389756aab6423d918a08ced468f05604df.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>. We cannot make this element using two resistors.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"c2a092afb5effd018c0843240bfb28c3\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"97388d8e9a3336f0fbcbc9a7e735a42b6679436b\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='c2a092afb5effd018c0843240bfb28c3'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F344%2Fproblem%2FC%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='c2a092afb5effd018c0843240bfb28c3'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/344\">Codeforces Round 200 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='c2a092afb5effd018c0843240bfb28c3'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/344/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Number theory: Euler function, GCD, divisibility, etc\">\r\n number theory\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1600\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='c2a092afb5effd018c0843240bfb28c3'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3464\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='c2a092afb5effd018c0843240bfb28c3'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3464\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8851\" title=\"Codeforces Round #200\" target=\"_blank\">Codeforces Round #200</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1854:1855\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8860\" title=\"Codeforces Round #200 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1850:1851\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/344\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/344/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/344/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/344/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/344/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/344/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/344/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/344/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_309a8deb4b2fad6de24d012af86772a8e9d8ad25\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Rational Resistance</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike is building a time machine in his spare time. To finish the work, he needs a resistor with a certain resistance value.</p><p>However, all Mike has is lots of identical resistors with unit resistance <span class=\"tex-span\"><i>R</i><sub class=\"lower-index\">0</sub> = 1</span>. Elements with other resistance can be constructed from these resistors. In this problem, we will consider the following as elements: </p><ol> <li> one resistor; </li><li> an element and <span class=\"tex-font-style-bf\">one</span> resistor plugged in sequence; </li><li> an element and <span class=\"tex-font-style-bf\">one</span> resistor plugged in parallel. </li></ol><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/fc5dca8df3a2578a728607daccf946b754d1cd00.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>With the consecutive connection the resistance of the new element equals <span class=\"tex-span\"><i>R</i> = <i>R</i><sub class=\"lower-index\"><i>e</i></sub> + <i>R</i><sub class=\"lower-index\">0</sub></span>. With the parallel connection the resistance of the new element equals <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/8e69f2f9d85e6584607971a68a207b22774fdf76.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. In this case <span class=\"tex-span\"><i>R</i><sub class=\"lower-index\"><i>e</i></sub></span> equals the resistance of the element being connected.</p><p>Mike needs to assemble an element with a resistance equal to the fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Determine the smallest possible number of resistors he needs to make such an element.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The single input line contains two space-separated integers <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span> (<span class=\"tex-span\">1 ≤ <i>a</i>, <i>b</i> ≤ 10<sup class=\"upper-index\">18</sup></span>). It is guaranteed that the fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> is irreducible. It is guaranteed that a solution always exists.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single number — the answer to the problem.</p><p>Please do not use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in С++. It is recommended to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>199 200<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>200<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample, one resistor is enough.</p><p>In the second sample one can connect the resistors in parallel, take the resulting element and connect it to a third resistor consecutively. Then, we get an element with resistance <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5305da389756aab6423d918a08ced468f05604df.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. We cannot make this element using two resistors.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:42</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bdaa38527597',t:'MTY5NjY0NjAyMi44MDgwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Mathematics including integration, differential equations, etc\", \"Number theory: Euler function, GCD, divisibility, etc\"]"},"short_tags":{"kind":"string","value":"[\"math\", \"number theory\", \"*1600\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8860"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"21ba25574a0615e5dc71db6e32a512d8\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #200 Tutorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #200 Tutorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='21ba25574a0615e5dc71db6e32a512d8'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8860\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/gen\">gen</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gen\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gen\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gen\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gen\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gen\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gen\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gen\" style=\"text-decoration:none;color:black !important;\">gen's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8915\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8860\"> <p>Codeforces Round #200 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a>,\r\n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h4><a href=\"/contest/344/problem/A\" title=\"Codeforces Round 200 (Div. 2)\">344A - Magnets</a></h4><p>By the definition each block consists of a number of consequent and equally oriented dominoes. That means that in places where adjacent dominoes are not oriented equally, one block ends and another block starts. So, if there are <span class=\"tex-span\"><i>x</i></span> such places, the answer is equal to <span class=\"tex-span\"><i>x</i> + 1</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> The problem was created a day before the contest and filled in the last part of a physically flavoured DivII complect. :]</p><h4><a href=\"/contest/344/problem/B\" title=\"Codeforces Round 200 (Div. 2)\">344B - Simple Molecules</a></h4><p>First solution. First, the sum <span class=\"tex-span\"><i>a</i> + <i>b</i> + <i>c</i></span> should be even, since each bond adds 2 to the sum. Now let <span class=\"tex-span\"><i>x</i></span>, <span class=\"tex-span\"><i>y</i></span>, <span class=\"tex-span\"><i>z</i></span> be the number of bonds between 1st and 2nd, 2nd and 3rd, 3rd and 1st atoms, accordingly. So we have to solve the system <span class=\"tex-span\"><i>x</i> + <i>z</i> = <i>a</i></span>, <span class=\"tex-span\"><i>y</i> + <i>x</i> = <i>b</i></span>, <span class=\"tex-span\"><i>z</i> + <i>y</i> = <i>c</i></span>. Now observe that the solution to the system is the length of the tangents on the triangle with sides of length <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span> to its inscribed circle, and are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/2cee22ffa44dda3ce1b315e8cceef38c6288cf2c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1aed1c363b13d01e1b412b9cd3d5e34d19eb9c96.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/30fbfc651674588cadbee1fedd1e4b0d08d1ad4e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. If the problem asked only the possibility of building such a molecule, we could just check if there exists (possibly degenerate) triangle with sides <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span>.</p><p><img alt=\" \" src=\"/predownloaded/e3/d3/e3d3c930f4f93ca68c1e61630a2771472ecbd60a.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Second solution. Bruteforce all <span class=\"tex-span\"><i>x</i></span> values. For a fixed <span class=\"tex-span\"><i>x</i></span> values of <span class=\"tex-span\"><i>y</i></span> and <span class=\"tex-span\"><i>z</i></span> are defined uniquely: <span class=\"tex-span\"><i>y</i> = <i>b</i> - <i>x</i></span>, <span class=\"tex-span\"><i>z</i> = <i>a</i> - <i>x</i></span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(1) / <i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> Can you solve the problem for any vertex number <span class=\"tex-span\"><i>n</i></span>? When and how can such a graph be built?</p><h4><a href=\"/contest/343/problem/A\" title=\"Codeforces Round 200 (Div. 1)\">343A - Rational Resistance</a></h4><p>If a fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> can be obtained with <span class=\"tex-span\"><i>k</i></span> resistors, then it is simple to calculate that we can obtain fractions <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b6913fd8136f518e8a7898a9b759b74c4d483101.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/daf9572f0aa7677d7961c329e6277818df63bd9f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> with <span class=\"tex-span\"><i>k</i> + 1</span> resistors. So adding one resistor means performing one operation backwards in Euclidean algorithm. That means that the answer is equal to the number of steps in standard Euclidean algorithm.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e847ae811adbd761fa24db4ba7a6827e0806d670.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Бонус:</strong> At first we thought about the major problem (any two elements can be joined), but had a moment of eureka and got that the given problem unexpectedly naturally can be reduced to GCD. By the way, the result tree — <a href=\"https://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree\">http://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree</a>.</p><h4><a href=\"/contest/343/problem/B\" title=\"Codeforces Round 200 (Div. 1)\">343B - Alternating Current</a></h4><p>Let us solve the following problem first: we are given a string of symbols A and B. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>A</i></span>, then at the <span class=\"tex-span\"><i>i</i></span>-th step the upper wire (see figure) is being put over the lower wire. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>B</i></span>, the lower wire is being put over the upper wire at <span class=\"tex-span\"><i>i</i></span>-th step. Observe that if some two symbols <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are adjacent, we can untangle this place, throw the symbols out and obtain the string of length two symbols less. So the wires can be untangled iff the number of A's and B's in the string is the same. The given problem can be reduced to the described in a following fashion: in each odd position we change – to B and + to A. In each even position we change — to A and + to B. The reduction is correct, since on each even position the order of — and + are always swapped, and in each odd position their order is the same as in the beginning.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> If you are interested by this problem, you can learn about the braid theory <a href=\"https://en.wikipedia.org/wiki/Braid_theory\">http://en.wikipedia.org/wiki/Braid_theory</a> :] Fun fact: a harder version of this problem was planned already for Round #142, but the error in solution idea was found, and the problem was left to lay for almost a year.</p><h4><a href=\"/contest/343/problem/C\" title=\"Codeforces Round 200 (Div. 1)\">343C - Read Time</a></h4><p>Let's search the answer <span class=\"tex-span\"><i>t</i></span> with the binary search. Fix some value of <span class=\"tex-span\"><i>t</i></span>. Look at the first head from the left <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> that can read track <span class=\"tex-span\"><i>p</i>[0]</span>. If <span class=\"tex-span\"><i>p</i>[0] > <i>h</i>[<i>i</i>]</span>, then <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> goes to the right <span class=\"tex-span\"><i>t</i></span> seconds and reads all tracks on its way. Otherwise if <span class=\"tex-span\"><i>p</i>[0] ≤ <i>h</i>[<i>i</i>]</span>, then the head has two choices:</p> <ol> <li>go to the right <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> seconds, then <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> to the left and <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> again to the left;</li> <li>go to the left <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> seconds, then <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> to the right and <span class=\"tex-span\"><i>t</i> - 2·(<i>h</i>[<i>i</i>] - <i>p</i>[0])</span> again to the right.</li> </ol><p>Obviously, for <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> it is more advantageous to visit the track positioned as much as possible to the right. So we choose by <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7edc4f5554e1d173945160b7deaca92e61d7a755.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Then we move the pointer onto the first unread track, and repeat the algorithm for <span class=\"tex-span\"><i>h</i>[<i>i</i> + 1]</span>, and so on with each head.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/3342f24e1fd6ab939313f6d6278245c95d89544f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a>.</p><p><strong>Bonus:</strong> The problem is completely real, if the disk has only a single head, if we know, what tracks should be read; then the optimal algorithm chooses between the two choices described above. I and <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a> were listening this on a lecture, and created the given problem out of boredom ;]</p><h4><a href=\"/contest/343/problem/D\" title=\"Codeforces Round 200 (Div. 1)\">343D - Water Tree</a></h4><p>Let's learn how to color a whole subtree. For that enumerate all vertices in post-order DFS. Then each subtree covers a single continious vertex number segment. For each vertex we store the bounds of such segment for a subtree with a root in this vertex. Then to color a subtree means to color a segment in a segment tree.</p><p>Then create a segment tree that has a following property: if a vertex <span class=\"tex-span\"><i>v</i></span> was emptied, and is still empty, then this vertex is colored in the segment tree. In the beginning "empty" all the vertices. That is, color all the vertices in the segment tree. With this tree we can efficiently process the queries:</p> <ol> <li><p>Fill a vertex <span class=\"tex-span\"><i>v</i></span>. Clean the interval for the subtree of <span class=\"tex-span\"><i>v</i></span>. If before that some vertex of a subtree was empty, color the parent of <span class=\"tex-span\"><i>v</i></span>.</p></li> <li><p>Empty a vertex <span class=\"tex-span\"><i>v</i></span>. Color the vertex <span class=\"tex-span\"><i>v</i></span> in the segment tree.</p></li> <li><p>Reply whether a vertex <span class=\"tex-span\"><i>v</i></span> is filled. If in the segment tree at least one vertex is colored, then there is such a descendant of <span class=\"tex-span\"><i>v</i></span> that is empty now, so the vertex <span class=\"tex-span\"><i>v</i></span> is not filled.</p></li> </ol><p><a class=\"rated-user user-blue\" href=\"/profile/Shtrix\" title=\"Expert Shtrix\">Shtrix</a> noted that essentially the same solution can be implemented with only a single set.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fcb5cb34164112e0db4b3ef4b921f55df7ffb005.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> Some participants could see the similarities with a problem Ball Machine from BOI 2013, but the solutions to the both problems are quite different.</p><h4><a href=\"/contest/343/problem/E\" title=\"Codeforces Round 200 (Div. 1)\">343E - Pumping Stations</a></h4><p>In this problem we are asked to find such graph vertex permutation that maximizes the sum of the maximum flows sent between each two consequtive vertices in the permutation.</p><p>The problem can be solved with <a href=\"https://en.wikipedia.org/wiki/Gomory%E2%80%93Hu_tree\">Gomory-Hu</a> tree data structure. For a given weighted graph the tree has the following properties:</p> <ol> <li>The vertex set of the tree and the graph is the same.</li> <li>The maximum flow between vertices <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> in the tree is equal to the maximum flow in the graph.</li> </ol><p>Surprisingly, such a tree exists for any weighted graph, and can be built in <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. It appears that the answer to the problem is equal to the sum of the edge weights in this tree.</p><p>We prove this statement by induction on the number of the tree vertices. Pick the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> with the smallest weight in the tree. Consider that in an optimal permutation more than one path between two adjacent verteces in the permutation passes through this edge. Erase all these paths, then each of the <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> subtrees holds a set of disjoint remaining paths from the permutation. For each set, join all the paths in one chain, obtaining two chains. These chains we join by a path <span class=\"tex-span\"><i>s</i></span> that goes trough the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>. Thus we have built a permutation that is not worse than the considered one. For a path <span class=\"tex-span\"><i>s</i></span> the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> is the smallest, so the flow along this path is equal to the weight of this edge. It follows from the induction that in subtrees <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> the answer is equal to the sum of edges. By adding the weight of edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>, we get the desired result.</p><p>From the last paragraph it is clear how to build such a permutation: take the smallest edge, obtain two chains from the vertex subtrees recursively, and add them together to form a one chain. Since there are not many vertices, we can do this part in <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-orange\" href=\"/profile/Gerald\" title=\"Master Gerald\">Gerald</a>.</p><p><strong>Bonus:</strong> Shortly before the contest we decided to make the constraints more loyal, so some solution that find Gomory-Hu tree by finding flow <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> times also passed. We hope that nobody is particularly saddened by this fact. (;</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/343\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/344\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-8915\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"8860\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=200\" class=\"tag notice\" style=\"text-decoration: none;\">200</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+64</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8860#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8860#comments\">\n 53\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8931\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (43)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145823\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bipinb1994\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/91315/avatar/b4e2d8ac5b2569a3.jpg'/> </a>\n <div><a href=\"/profile/bipinb1994\" title=\"Expert bipinb1994\" class=\"rated-user user-blue\">bipinb1994</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 07:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145823\" href=\"?#comment-145823\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145823\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-15\"\r\n data-commentUserId=\"91315\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145823\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hai this was my first round in Codeforces. But my code was not accepted and it says that it was wrong with the 3rd test case. What i did was put a loop from 0 to n-1 and i checked ch[i][!=ch[i+1][0] then count++; else continue where 'ch' is the character array(2-D) whose size was Nx3 ...Is this algorithm completely wrong. As i said this was the first round here i did not understand what is wrong with this. If possible please do tell me what is wrong with this algorithm..:(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145823 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145823 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145823\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145863\" commentParentId=\"145823\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 14:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145863\" href=\"?#comment-145863\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145823\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145863\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145863\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please look at link <a href=\"//codeforces.com/contest/344/submission/4461494\">http://codeforces.com/contest/344/submission/4461494</a>. </p><p>The log says</p><p>Time: 0 ms, memory: 0 KB Verdict: WRONG_ANSWER Input 1 10 Output 0 Answer 1 Checker comment wrong answer 1st numbers differ — expected: '1', found: '0'</p><p>I believe this should be self explanatory. </p><p>Also it would help playing around with the system before trying to enter a rated match.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145863 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145863 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145863\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146026\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ka16\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ka16\" title=\"Pupil ka16\" class=\"rated-user user-green\">ka16</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 06:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146026\" href=\"?#comment-146026\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146026\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"12131\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146026\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody please clarify the two choices of head(s) in the solution of 343C-Read Time problem above? I couldn't understand it completely. Thank in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146026 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146026 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146026\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146037\" commentParentId=\"146026\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hriss95\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27396/avatar/d6cec8eac7bdbde3.jpg'/> </a>\n <div><a href=\"/profile/hriss95\" title=\"Expert hriss95\" class=\"rated-user user-blue\">hriss95</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 13:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146037\" href=\"?#comment-146037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146026\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146037\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"27396\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have to choose one of the two types moving: first to the right or first to the left. You have to use the one which covers more points to the right. Note that both types of moving cover the left point and that's why you have to take as much as points as you can to the right.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146037\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sorin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/sorin\" title=\"Expert sorin\" class=\"rated-user user-blue\">sorin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 12:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146034\" href=\"?#comment-146034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"124904\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody give me a hint for the bonus at Div2 — B? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146034\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146064\" commentParentId=\"146034\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 21:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146064\" href=\"?#comment-146064\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146034\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146064\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146064\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Think greedy ;]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146064 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146064 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146064\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"152157\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ghooo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2010/avatar/659a8aca8b12506a.jpg'/> </a>\n <div><a href=\"/profile/ghooo\" title=\"Master ghooo\" class=\"rated-user user-orange\">ghooo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/26/2013 08:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-152157\" href=\"?#comment-152157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"152157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2010\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-152157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>will the connections between the atoms be circular? like 1 <-> 2 <-> 3 <-> 4 <-> 5 ... n <-> 1 (again) ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-152157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-152157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-152157\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"521750\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/n0tred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1177564/avatar/a46e0281e87dd6c9.jpg'/> </a>\n <div><a href=\"/profile/n0tred\" title=\"Candidate Master n0tred\" class=\"rated-user user-violet\">n0tred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/25/2019 14:29\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-521750\" href=\"?#comment-521750\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"521750\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1177564\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-521750\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you give a better hint? (Maybe through a spoiler, I suppose)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-521750 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-521750 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-521750\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"523308\" commentParentId=\"521750\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/29/2019 09:36\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-523308\" href=\"?#comment-523308\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-521750\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"523308\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-523308\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the algorithm that continuously connects the vertex with the smallest degree with the vertex with the largest degree works (here by degree I mean the unconnected edges), and builds a connected graph. I think this can be proved by induction.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-523308 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-523308 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-523308\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146129\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 11:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146129\" href=\"?#comment-146129\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146129\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146129\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think there is an issue with Problem 343A — Rational Resistance. Here according to the editorial the answer to the ratio 6/5 would be 6(I have verified this with an accepted solution). But this ratio can be achieved with a resistance of 2 and 3 in parallel, which makes the number of resistors required equal to 5 which would imply the editorial and the system tests to be wrong.</p><p>Am I missing something here?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146129 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146129 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146129\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146259\" commentParentId=\"146129\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146259\" href=\"?#comment-146259\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146129\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146259\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146259\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think it's because the definition of <strong>one element</strong> only let you add <strong>one</strong> new unit resistor to another element</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146259 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146259 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146259\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146256\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146256\" href=\"?#comment-146256\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146256\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146256\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for the nice problems!</p><p>I just have a little question on 343C — Read Time. I use the same algorithm and get AC, but my algorithm is running at O(n log^2 n)... as for the step: "Then we move the pointer onto the first unread track" I use another binary search...</p><p>how can I implement the same algorithm with O(n log n) as said in editorial? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146256 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146256 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146256\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146269\" commentParentId=\"146256\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146269\" href=\"?#comment-146269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146256\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146269\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We hold two pointers: the first points at the first unread track from the left, and the second points at the first unused head so far. So we take this head and read with its help the maximum number of yet unread tracks (note that they are consequent and begin at the first pointer) according to the best of the two choices described in tutorial. Then we move the first pointer to the first yet unread track, and increment the second by one. Thus each pointer moves <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> times in this iteration of the binary search. Take also in consideration that some heads can be not used at all.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154161\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/s2k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146708/avatar/ec43946f377e5c64.jpg'/> </a>\n <div><a href=\"/profile/s2k\" title=\"Newbie s2k\" class=\"rated-user user-gray\">s2k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154161\" href=\"?#comment-154161\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154161\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146708\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154161\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi. I was just trying to solve problem A of division 2, but was unsuccessful after hours of effort. I eventually lost patience and decided to see the codes of others. I did understand what was going in the code, but couldn't figure out why this method was chosen in the first place. Can someone please help me understand the solution?</p><p>P.S. I'm a newbie with almost no prior knowledge about number theory. :$</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154161 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154161 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154161\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154163\" commentParentId=\"154161\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154163\" href=\"?#comment-154163\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-154161\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154163\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154163\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The number of islands is always one more than the number of splits between two neighboring dominoes. One can easily convince himself by looking at an image in the description.</p><p>There are 4 possibilities of neighboring dominoes:</p> <ul> <li>01 and 01: these attract, so they don't form a split and we don't care about them</li> <li>10 and 10: these attract, so they don't form a split and we don't care about them</li> <li>01 and 10: these don't attract, so they form a split</li> <li>10 and 01: these don't attract, so they form a split</li> </ul><p>So, we can deduce that we're only interested in neighboring dominoes that are different. This means we can just count the number of indexes i (1 <= i < N) such that s[i] != s[i+1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154163 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154163 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154163\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176652\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/S.Ged\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67184/avatar/a38f51555a40b56a.jpg'/> </a>\n <div><a href=\"/profile/S.Ged\" title=\"Candidate Master S.Ged\" class=\"rated-user user-violet\">S.Ged</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 04:10\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176652\" href=\"?#comment-176652\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"176652\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"176652\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"67184\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176652\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm confused by the first sentence of 343A — Rational Resistance tutorial</p><p>How can we obtain a/(a+b) with k+1 resistors if obatined a/b wiht k resistors ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176652 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176652 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176652\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176656\" commentParentId=\"176652\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/afrizal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/103639/avatar/206f6cf479b00060.jpg'/> </a>\n <div><a href=\"/profile/afrizal\" title=\"Expert afrizal\" class=\"rated-user user-blue\">afrizal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 07:05\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176656\" href=\"?#comment-176656\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176652\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"176656\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"103639\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176656\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Remember a/a is 1. If we have a/b resistance, put one more resistor parallel will give <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c1a16b55f7f10840909e0e5863ae3ce22e36c85b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176656 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176656 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176656\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"189636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/namikaze\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/227989/avatar/51e67e9e139a65f2.jpg'/> </a>\n <div><a href=\"/profile/namikaze\" title=\"Unrated, namikaze\" class=\"rated-user user-black\">namikaze</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/28/2014 15:45\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-189636\" href=\"?#comment-189636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"189636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"227989\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-189636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><code>adding one resistor means performing one operation backwards in Euclidean algorithm</code></p><p>Can someone explain this ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-189636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-189636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-189636\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"277029\" commentParentId=\"189636\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TomBombadil\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/106415/avatar/ed9d8ef375273241.jpg'/> </a>\n <div><a href=\"/profile/TomBombadil\" title=\"Specialist TomBombadil\" class=\"rated-user user-cyan\">TomBombadil</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2016 17:50\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-277029\" href=\"?#comment-277029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-189636\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"277029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"106415\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-277029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-orange\" href=\"/profile/gen\" title=\"Master gen\">gen</a> ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-277029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-277029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-277029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"351231\" commentParentId=\"277029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/R.A.X\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/122476/avatar/686763c746ac6e7b.jpg'/> </a>\n <div><a href=\"/profile/R.A.X\" title=\"Specialist R.A.X\" class=\"rated-user user-cyan\">R.A.X</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/27/2017 15:37\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-351231\" href=\"?#comment-351231\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-277029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"351231\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"351231\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"122476\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-351231\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Suppose you have resistance of(17/3), it could be formed by adding 1 + (14/3). If you have resistance of (3/17), it could be obtained by combining resistance of 1 and 3/14 in parallel.</p><p>In terms of variable, a/b could be obtained by 1 + resistors required to create ( a-b)/b resistance, assuming a>b. and a/b if b>a, could be obtained by 1 + resistors required to create ( a/(b-a) ).</p><p>Assuming a>b so resistorRequired(a,b) = 1 + resistorRequired(a-b,b).</p> <pre>resistorReqiored(a-b,b) = 1 + resistorRequired(a-2b,b)</pre><p>............</p> <pre>resistorRequired(a-(q-1)*b ,b) = 1 + resistorRequired(a-q*b,b)</pre><p>let say r = a-q*b == a%b now at this point, one resistance needs to be connected in parallel to the b/r resistance.</p><p>so again problem becomes calculating the requiredResistance(b,r) similar to above problem,</p><p>which is similar to the gcd problem.</p><p>Hope that helps.</p><p>Why it's like gcd(a,b) = gcd(a-b,b) =gcd(a-2b,b) .... </p><p>In case of gcd(a,b) = gcd(a-b,b)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-351231 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-351231 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-351231\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"393063\" commentParentId=\"351231\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ShafinKhadem\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/508696/avatar/1b5c8ae9cf51dc77.jpg'/> </a>\n <div><a href=\"/profile/ShafinKhadem\" title=\"Master ShafinKhadem\" class=\"rated-user user-orange\">ShafinKhadem</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/01/2017 09:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-393063\" href=\"?#comment-393063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-351231\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"393063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"508696\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-393063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for the nice explanation. Now the use of euclidian algorithm to solve this problem makes sense to me.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-393063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-393063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-393063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"220282\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CloverAsta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207753/avatar/45b71a38344fa830.jpg'/> </a>\n <div><a href=\"/profile/CloverAsta\" title=\"Expert CloverAsta\" class=\"rated-user user-blue\">CloverAsta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/01/2015 14:33\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-220282\" href=\"?#comment-220282\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"220282\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207753\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-220282\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain to me the solution for Problem C div2 I understand the transition from <code>k</code> to <code>k + 1</code> but the part about Euclidean algorithm is beyond me</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-220282 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-220282 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-220282\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"232136\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anajin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221428/avatar/b8f5979933e2ce3d.jpg'/> </a>\n <div><a href=\"/profile/anajin\" title=\"Expert anajin\" class=\"rated-user user-blue\">anajin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/03/2015 14:15\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-232136\" href=\"?#comment-232136\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"232136\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-232136\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>water tree can be solved by heavy-light decomposition...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-232136 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-232136 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-232136\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"454886\" commentParentId=\"232136\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cai_lw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/325977/avatar/202b61935928944.jpg'/> </a>\n <div><a href=\"/profile/cai_lw\" title=\"International Master cai_lw\" class=\"rated-user user-orange\">cai_lw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/30/2018 20:04\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-454886\" href=\"?#comment-454886\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-232136\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"454886\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"454886\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"325977\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-454886\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, this is almost the most standard problem for HLD. But their solution is cleverer and has lower time complexity. HLD is a little bit overkill for such simple operations.</p><p>Nevertheless, HLD can pass the test. My HLD solution passed in 900ms.</p><p>Also HLD was a relatively unknown algorithm to the CP community 5 years ago.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-454886 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-454886 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-454886\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"634570\" commentParentId=\"454886\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Suri429\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/776807/avatar/90399ec92a81320a.jpg'/> </a>\n <div><a href=\"/profile/Suri429\" title=\"Master Suri429\" class=\"rated-user user-orange\">Suri429</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2020 08:55\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-634570\" href=\"?#comment-634570\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-454886\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"634570\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"776807\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-634570\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain how to approach this with HLD? I am new to HLD, and not able to get any clue here. </p><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-634570 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-634570 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-634570\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"312598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/29/2016 12:31\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-312598\" href=\"?#comment-312598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"312598\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"312598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-312598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder why I did wrong in the implementation of lazy propagation for Div1D, could anyone kindly lend some help? </p><p><a href=\"//codeforces.com/contest/343/submission/20226349\">http://codeforces.com/contest/343/submission/20226349</a></p><p>Thanks in advance. =)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-312598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-312598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-312598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"357445\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anshulgarg19\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/anshulgarg19\" title=\"Pupil anshulgarg19\" class=\"rated-user user-green\">anshulgarg19</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/02/2017 20:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-357445\" href=\"?#comment-357445\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"357445\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"244328\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-357445\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Accepted solution for the problem 343A Rational Resistance would give 6 as the output for input a = 10 and b = 7 i.e.10/7. But, if we have 5 ohm and 2 ohm resistors in parallel, then we have the same resistance value 10/7. So minimum value should be 2 resistors for this case. Kindly explain if i am wrong in understanding the problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-357445 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-357445 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-357445\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360009\" commentParentId=\"357445\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/snehil10\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/351506/avatar/522f61633a219a3b.jpg'/> </a>\n <div><a href=\"/profile/snehil10\" title=\"Expert snehil10\" class=\"rated-user user-blue\">snehil10</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/14/2017 10:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360009\" href=\"?#comment-360009\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-357445\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"360009\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"351506\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360009\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have only 1-ohm resistors in the beginning. Thus it requires 5 1-ohm resistors to make a 5-ohm resistor, and 2 1-ohm resistors to make a 2-ohm resistor. So according to you answer is 7 and not 2.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360009 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360009 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360009\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371475\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rush_123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/rush_123\" title=\"Expert rush_123\" class=\"rated-user user-blue\">rush_123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/03/2017 17:42\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371475\" href=\"?#comment-371475\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"371475\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"439840\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371475\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 343D — Water Tree query 1 and 2 can be solved using a dfs to find in time and out time for every node and then using segment tree But what about 3rd query how to solve it?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371475 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371475 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371475\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"422269\" commentParentId=\"371475\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stringray\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/575608/avatar/2902babcf56868a2.jpg'/> </a>\n <div><a href=\"/profile/stringray\" title=\"Expert stringray\" class=\"rated-user user-blue\">stringray</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/28/2018 16:13\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-422269\" href=\"?#comment-422269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371475\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"422269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"575608\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-422269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yeah same question .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-422269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-422269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-422269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"437012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ragnarok_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ragnarok_\" title=\"Newbie ragnarok_\" class=\"rated-user user-gray\">ragnarok_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2018 08:59\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-437012\" href=\"?#comment-437012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"437012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"673189\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-437012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Q.343A can anybody explain me why min resistor for 199/200 is 200.....it can be also constructed using 101 resistors(1/2+1/4+1/5+1/40+1/50)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-437012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-437012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-437012\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"573631\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SLIMSHADYNICK\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/598862/avatar/7629f1b29f0fe807.jpg'/> </a>\n <div><a href=\"/profile/SLIMSHADYNICK\" title=\"Candidate Master SLIMSHADYNICK\" class=\"rated-user user-violet\">SLIMSHADYNICK</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2020 21:03\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-573631\" href=\"?#comment-573631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"573631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"598862\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-573631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>correct!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-573631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-573631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-573631\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587715\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pied-piper\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/754580/avatar/a6fb81d49bb96665.jpg'/> </a>\n <div><a href=\"/profile/pied-piper\" title=\"Expert pied-piper\" class=\"rated-user user-blue\">pied-piper</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/11/2020 16:14\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587715\" href=\"?#comment-587715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"587715\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"587715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"754580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It is because they are separate elements and hence they cannot be added together. Only an element and a 1 unit resistance can be added in series(or parallel)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587715\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"791297\" commentParentId=\"587715\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/15/2021 17:25\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-791297\" href=\"?#comment-791297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587715\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"791297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-791297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-791297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-791297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-791297\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"598229\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayank_ag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/644568/avatar/c1136e364e721d18.jpg'/> </a>\n <div><a href=\"/profile/mayank_ag\" title=\"Master mayank_ag\" class=\"rated-user user-orange\">mayank_ag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/05/2020 20:53\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-598229\" href=\"?#comment-598229\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"598229\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"644568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-598229\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>An alternate approach for solving D: Use of lazy segment tree over HLD & Euler path. For every filling, fill Euler path with current query number, and for emptying, fill HLD path from the root with query number. For queries, check which of the seg tree has high query number.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-598229 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-598229 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-598229\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"600816\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Asterix_11\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Asterix_11\" title=\"Pupil Asterix_11\" class=\"rated-user user-green\">Asterix_11</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/11/2020 00:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-600816\" href=\"?#comment-600816\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"600816\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1472760\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-600816\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem 344A</p> <pre><code>#include <iostream>\nusing namespace std;\nint main()\n{\n int a, i, b[100], ans;\n scanf("%d", &a);\n for(i = 0; i < a; ++i){\n scanf("%d", &b[i]);\n }\n ans = 1;\n for(i = 0; i < (a-1); ++i){\n if(b[i] != b[i + 1]){\n ++ans;}\n }\n printf("%d", ans);\n return 0;\n}\n</code></pre><p>This is my code, but I don't know how to improve it, so that the time limit won't be a problem anymore. Any help?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-600816 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-600816 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-600816\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752098\" commentParentId=\"600816\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 09:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752098\" href=\"?#comment-752098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-600816\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can make two variable for prev and current value and if they are not equal you can increment it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752098\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752075\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:25\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752075\" href=\"?#comment-752075\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752075\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752075\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Problem C, if more than one of the elements can be in parallel than for ratio 199 and 200 the answer given is 200. But we may solve this in 74. like 1/2+1/4+1/8+1/10+1/50.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752075 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752075 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752075\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752089\" commentParentId=\"752075\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752089\" href=\"?#comment-752089\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-752075\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752089\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752089\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Okay it would be like either + denominator to the numerator or + numerator to the denominator.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752089 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752089 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752089\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"946539\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mohsina_Shaikh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1396580/avatar/6f21616a2d8d578.jpg'/> </a>\n <div><a href=\"/profile/Mohsina_Shaikh\" title=\"Newbie Mohsina_Shaikh\" class=\"rated-user user-gray\">Mohsina_Shaikh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/24/2022 06:47\">13 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-946539\" href=\"?#comment-946539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"946539\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"946539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1396580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-946539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a> or <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a> or can anyone please explain <code>Alternating Current</code> Solution.Tried so hard but not able to understand it. A</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-946539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-946539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-946539\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"959164\" commentParentId=\"946539\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rishijoshi483\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2453886/avatar/1ecf48b346fe39d0.jpg'/> </a>\n <div><a href=\"/profile/rishijoshi483\" title=\"Expert rishijoshi483\" class=\"rated-user user-blue\">rishijoshi483</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/03/2022 09:44\">12 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-959164\" href=\"?#comment-959164\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-946539\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"959164\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2453886\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-959164\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try it using stack</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-959164 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-959164 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-959164\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"966651\" commentParentId=\"959164\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Yohajji\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2854745/avatar/b31d6e4c63852741.jpg'/> </a>\n <div><a href=\"/profile/Yohajji\" title=\"Newbie Yohajji\" class=\"rated-user user-gray\">Yohajji</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2022 13:35\">11 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-966651\" href=\"?#comment-966651\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-959164\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"966651\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2854745\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-966651\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>using the stack was a brilliant aproach, thank you </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-966651 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-966651 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-966651\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1039007\" commentParentId=\"966651\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AbdelrahmanMahallawy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3189297/avatar/6b2a1658ad37caa0.jpg'/> </a>\n <div><a href=\"/profile/AbdelrahmanMahallawy\" title=\"Newbie AbdelrahmanMahallawy\" class=\"rated-user user-gray\">AbdelrahmanMahallawy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/20/2023 03:36\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1039007\" href=\"?#comment-1039007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-966651\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1039007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3189297\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1039007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>anytime </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1039007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1039007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1039007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8931\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8931 = true;\r\nvar lastPreviewContent8931 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8931] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8931] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:23</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128748fcb8816ab',t:'MTY5NjcwNTk0My4yOTkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1745,"cells":{"problem_id":{"kind":"string","value":"344D"},"contest":{"kind":"string","value":"344"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Alternating Current"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Alternating Current</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike has just finished constructing a new device to search for extraterrestrial intelligence! He was in such a hurry to launch it for the first time that he plugged in the power wires without giving it a proper glance and started experimenting right away. After a while Mike observed that the wires ended up entangled and now have to be untangled again.</p><p>The device is powered by two wires \"plus\" and \"minus\". The wires run along the floor from the wall (on the left) to the device (on the right). Both the wall and the device have two contacts in them on the same level, into which the wires are plugged in some order. The wires are considered entangled if there are one or more places where one wire runs above the other one. For example, the picture below has four such places (top view):</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/d9893064977f0a3ba06c4b18908f20c7ef488731.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>Mike knows the sequence in which the wires run above each other. Mike also noticed that on the left side, the \"plus\" wire is always plugged into the top contact (as seen on the picture). He would like to untangle the wires without unplugging them and <span class=\"tex-font-style-bf\">without moving</span> the device. Determine if it is possible to do that. A wire can be freely moved and stretched on the floor, but cannot be cut.</p><p>To understand the problem better please read the notes to the test samples.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The single line of the input contains a sequence of characters \"<span class=\"tex-font-style-tt\">+</span>\" and \"<span class=\"tex-font-style-tt\">-</span>\" of length <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100000</span>). The <span class=\"tex-span\"><i>i</i></span>-th (<span class=\"tex-span\">1 ≤ <i>i</i> ≤ <i>n</i></span>) position of the sequence contains the character \"<span class=\"tex-font-style-tt\">+</span>\", if on the <span class=\"tex-span\"><i>i</i></span>-th step from the wall the \"plus\" wire runs above the \"minus\" wire, and the character \"<span class=\"tex-font-style-tt\">-</span>\" otherwise.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print either \"<span class=\"tex-font-style-tt\">Yes</span>\" (without the quotes) if the wires can be untangled or \"<span class=\"tex-font-style-tt\">No</span>\" (without the quotes) if the wires cannot be untangled.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>-++-<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Yes<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>+-<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>No<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>++<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Yes<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>-<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>No<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The first testcase corresponds to the picture in the statement. To untangle the wires, one can first move the \"plus\" wire lower, thus eliminating the two crosses in the middle, and then draw it under the \"minus\" wire, eliminating also the remaining two crosses.</p><p>In the second testcase the \"plus\" wire makes one full revolution around the \"minus\" wire. Thus the wires cannot be untangled: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/ab7cf5aedea609efdfcd91bf5ece433ff50d80fe.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>In the third testcase the \"plus\" wire simply runs above the \"minus\" wire twice in sequence. The wires can be untangled by lifting \"plus\" and moving it higher: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/c3d652f33419ce743e0f2e4e951b77f90915151b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>In the fourth testcase the \"minus\" wire runs above the \"plus\" wire once. The wires cannot be untangled without moving the device itself: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/ca61897e6664278c14115d010a07b6023c28e833.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"54bea1f04fd3406e98d34ebc8483c788\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"97388d8e9a3336f0fbcbc9a7e735a42b6679436b\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='54bea1f04fd3406e98d34ebc8483c788'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F344%2Fproblem%2FD%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='54bea1f04fd3406e98d34ebc8483c788'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/344\">Codeforces Round 200 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='54bea1f04fd3406e98d34ebc8483c788'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/344/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Heaps, binary search trees, segment trees, hash tables, etc\">\r\n data structures\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1600\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='54bea1f04fd3406e98d34ebc8483c788'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3465\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='54bea1f04fd3406e98d34ebc8483c788'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3465\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8851\" title=\"Codeforces Round #200\" target=\"_blank\">Codeforces Round #200</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1854:1855\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8860\" title=\"Codeforces Round #200 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1850:1851\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/344\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/344/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/344/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/344/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/344/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/344/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/344/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/344/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_18ba5d8a6bbca2abe1dada7b39cff82d0b969d4d\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Alternating Current</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike has just finished constructing a new device to search for extraterrestrial intelligence! He was in such a hurry to launch it for the first time that he plugged in the power wires without giving it a proper glance and started experimenting right away. After a while Mike observed that the wires ended up entangled and now have to be untangled again.</p><p>The device is powered by two wires "plus" and "minus". The wires run along the floor from the wall (on the left) to the device (on the right). Both the wall and the device have two contacts in them on the same level, into which the wires are plugged in some order. The wires are considered entangled if there are one or more places where one wire runs above the other one. For example, the picture below has four such places (top view):</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/d9893064977f0a3ba06c4b18908f20c7ef488731.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>Mike knows the sequence in which the wires run above each other. Mike also noticed that on the left side, the "plus" wire is always plugged into the top contact (as seen on the picture). He would like to untangle the wires without unplugging them and <span class=\"tex-font-style-bf\">without moving</span> the device. Determine if it is possible to do that. A wire can be freely moved and stretched on the floor, but cannot be cut.</p><p>To understand the problem better please read the notes to the test samples.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The single line of the input contains a sequence of characters "<span class=\"tex-font-style-tt\">+</span>" and "<span class=\"tex-font-style-tt\">-</span>" of length <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100000</span>). The <span class=\"tex-span\"><i>i</i></span>-th (<span class=\"tex-span\">1 ≤ <i>i</i> ≤ <i>n</i></span>) position of the sequence contains the character "<span class=\"tex-font-style-tt\">+</span>", if on the <span class=\"tex-span\"><i>i</i></span>-th step from the wall the "plus" wire runs above the "minus" wire, and the character "<span class=\"tex-font-style-tt\">-</span>" otherwise.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print either "<span class=\"tex-font-style-tt\">Yes</span>" (without the quotes) if the wires can be untangled or "<span class=\"tex-font-style-tt\">No</span>" (without the quotes) if the wires cannot be untangled.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>-++-<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Yes<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>+-<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>No<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>++<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Yes<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>-<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>No<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The first testcase corresponds to the picture in the statement. To untangle the wires, one can first move the "plus" wire lower, thus eliminating the two crosses in the middle, and then draw it under the "minus" wire, eliminating also the remaining two crosses.</p><p>In the second testcase the "plus" wire makes one full revolution around the "minus" wire. Thus the wires cannot be untangled: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/ab7cf5aedea609efdfcd91bf5ece433ff50d80fe.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>In the third testcase the "plus" wire simply runs above the "minus" wire twice in sequence. The wires can be untangled by lifting "plus" and moving it higher: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/c3d652f33419ce743e0f2e4e951b77f90915151b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>In the fourth testcase the "minus" wire runs above the "plus" wire once. The wires cannot be untangled without moving the device itself: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/ca61897e6664278c14115d010a07b6023c28e833.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:44</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bdb268233a65',t:'MTY5NjY0NjAyNC4xNDIwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Heaps, binary search trees, segment trees, hash tables, etc\", \"Greedy algorithms\", \"Implementation problems, programming technics, simulation\"]"},"short_tags":{"kind":"string","value":"[\"data structures\", \"greedy\", \"implementation\", \"*1600\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8860"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"21ba25574a0615e5dc71db6e32a512d8\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #200 Tutorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #200 Tutorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='21ba25574a0615e5dc71db6e32a512d8'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8860\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/gen\">gen</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gen\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gen\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gen\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gen\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gen\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gen\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gen\" style=\"text-decoration:none;color:black !important;\">gen's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8915\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8860\"> <p>Codeforces Round #200 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a>,\r\n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h4><a href=\"/contest/344/problem/A\" title=\"Codeforces Round 200 (Div. 2)\">344A - Magnets</a></h4><p>By the definition each block consists of a number of consequent and equally oriented dominoes. That means that in places where adjacent dominoes are not oriented equally, one block ends and another block starts. So, if there are <span class=\"tex-span\"><i>x</i></span> such places, the answer is equal to <span class=\"tex-span\"><i>x</i> + 1</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> The problem was created a day before the contest and filled in the last part of a physically flavoured DivII complect. :]</p><h4><a href=\"/contest/344/problem/B\" title=\"Codeforces Round 200 (Div. 2)\">344B - Simple Molecules</a></h4><p>First solution. First, the sum <span class=\"tex-span\"><i>a</i> + <i>b</i> + <i>c</i></span> should be even, since each bond adds 2 to the sum. Now let <span class=\"tex-span\"><i>x</i></span>, <span class=\"tex-span\"><i>y</i></span>, <span class=\"tex-span\"><i>z</i></span> be the number of bonds between 1st and 2nd, 2nd and 3rd, 3rd and 1st atoms, accordingly. So we have to solve the system <span class=\"tex-span\"><i>x</i> + <i>z</i> = <i>a</i></span>, <span class=\"tex-span\"><i>y</i> + <i>x</i> = <i>b</i></span>, <span class=\"tex-span\"><i>z</i> + <i>y</i> = <i>c</i></span>. Now observe that the solution to the system is the length of the tangents on the triangle with sides of length <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span> to its inscribed circle, and are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/2cee22ffa44dda3ce1b315e8cceef38c6288cf2c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1aed1c363b13d01e1b412b9cd3d5e34d19eb9c96.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/30fbfc651674588cadbee1fedd1e4b0d08d1ad4e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. If the problem asked only the possibility of building such a molecule, we could just check if there exists (possibly degenerate) triangle with sides <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span>.</p><p><img alt=\" \" src=\"/predownloaded/e3/d3/e3d3c930f4f93ca68c1e61630a2771472ecbd60a.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Second solution. Bruteforce all <span class=\"tex-span\"><i>x</i></span> values. For a fixed <span class=\"tex-span\"><i>x</i></span> values of <span class=\"tex-span\"><i>y</i></span> and <span class=\"tex-span\"><i>z</i></span> are defined uniquely: <span class=\"tex-span\"><i>y</i> = <i>b</i> - <i>x</i></span>, <span class=\"tex-span\"><i>z</i> = <i>a</i> - <i>x</i></span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(1) / <i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> Can you solve the problem for any vertex number <span class=\"tex-span\"><i>n</i></span>? When and how can such a graph be built?</p><h4><a href=\"/contest/343/problem/A\" title=\"Codeforces Round 200 (Div. 1)\">343A - Rational Resistance</a></h4><p>If a fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> can be obtained with <span class=\"tex-span\"><i>k</i></span> resistors, then it is simple to calculate that we can obtain fractions <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b6913fd8136f518e8a7898a9b759b74c4d483101.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/daf9572f0aa7677d7961c329e6277818df63bd9f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> with <span class=\"tex-span\"><i>k</i> + 1</span> resistors. So adding one resistor means performing one operation backwards in Euclidean algorithm. That means that the answer is equal to the number of steps in standard Euclidean algorithm.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e847ae811adbd761fa24db4ba7a6827e0806d670.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Бонус:</strong> At first we thought about the major problem (any two elements can be joined), but had a moment of eureka and got that the given problem unexpectedly naturally can be reduced to GCD. By the way, the result tree — <a href=\"https://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree\">http://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree</a>.</p><h4><a href=\"/contest/343/problem/B\" title=\"Codeforces Round 200 (Div. 1)\">343B - Alternating Current</a></h4><p>Let us solve the following problem first: we are given a string of symbols A and B. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>A</i></span>, then at the <span class=\"tex-span\"><i>i</i></span>-th step the upper wire (see figure) is being put over the lower wire. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>B</i></span>, the lower wire is being put over the upper wire at <span class=\"tex-span\"><i>i</i></span>-th step. Observe that if some two symbols <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are adjacent, we can untangle this place, throw the symbols out and obtain the string of length two symbols less. So the wires can be untangled iff the number of A's and B's in the string is the same. The given problem can be reduced to the described in a following fashion: in each odd position we change – to B and + to A. In each even position we change — to A and + to B. The reduction is correct, since on each even position the order of — and + are always swapped, and in each odd position their order is the same as in the beginning.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> If you are interested by this problem, you can learn about the braid theory <a href=\"https://en.wikipedia.org/wiki/Braid_theory\">http://en.wikipedia.org/wiki/Braid_theory</a> :] Fun fact: a harder version of this problem was planned already for Round #142, but the error in solution idea was found, and the problem was left to lay for almost a year.</p><h4><a href=\"/contest/343/problem/C\" title=\"Codeforces Round 200 (Div. 1)\">343C - Read Time</a></h4><p>Let's search the answer <span class=\"tex-span\"><i>t</i></span> with the binary search. Fix some value of <span class=\"tex-span\"><i>t</i></span>. Look at the first head from the left <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> that can read track <span class=\"tex-span\"><i>p</i>[0]</span>. If <span class=\"tex-span\"><i>p</i>[0] > <i>h</i>[<i>i</i>]</span>, then <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> goes to the right <span class=\"tex-span\"><i>t</i></span> seconds and reads all tracks on its way. Otherwise if <span class=\"tex-span\"><i>p</i>[0] ≤ <i>h</i>[<i>i</i>]</span>, then the head has two choices:</p> <ol> <li>go to the right <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> seconds, then <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> to the left and <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> again to the left;</li> <li>go to the left <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> seconds, then <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> to the right and <span class=\"tex-span\"><i>t</i> - 2·(<i>h</i>[<i>i</i>] - <i>p</i>[0])</span> again to the right.</li> </ol><p>Obviously, for <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> it is more advantageous to visit the track positioned as much as possible to the right. So we choose by <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7edc4f5554e1d173945160b7deaca92e61d7a755.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Then we move the pointer onto the first unread track, and repeat the algorithm for <span class=\"tex-span\"><i>h</i>[<i>i</i> + 1]</span>, and so on with each head.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/3342f24e1fd6ab939313f6d6278245c95d89544f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a>.</p><p><strong>Bonus:</strong> The problem is completely real, if the disk has only a single head, if we know, what tracks should be read; then the optimal algorithm chooses between the two choices described above. I and <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a> were listening this on a lecture, and created the given problem out of boredom ;]</p><h4><a href=\"/contest/343/problem/D\" title=\"Codeforces Round 200 (Div. 1)\">343D - Water Tree</a></h4><p>Let's learn how to color a whole subtree. For that enumerate all vertices in post-order DFS. Then each subtree covers a single continious vertex number segment. For each vertex we store the bounds of such segment for a subtree with a root in this vertex. Then to color a subtree means to color a segment in a segment tree.</p><p>Then create a segment tree that has a following property: if a vertex <span class=\"tex-span\"><i>v</i></span> was emptied, and is still empty, then this vertex is colored in the segment tree. In the beginning "empty" all the vertices. That is, color all the vertices in the segment tree. With this tree we can efficiently process the queries:</p> <ol> <li><p>Fill a vertex <span class=\"tex-span\"><i>v</i></span>. Clean the interval for the subtree of <span class=\"tex-span\"><i>v</i></span>. If before that some vertex of a subtree was empty, color the parent of <span class=\"tex-span\"><i>v</i></span>.</p></li> <li><p>Empty a vertex <span class=\"tex-span\"><i>v</i></span>. Color the vertex <span class=\"tex-span\"><i>v</i></span> in the segment tree.</p></li> <li><p>Reply whether a vertex <span class=\"tex-span\"><i>v</i></span> is filled. If in the segment tree at least one vertex is colored, then there is such a descendant of <span class=\"tex-span\"><i>v</i></span> that is empty now, so the vertex <span class=\"tex-span\"><i>v</i></span> is not filled.</p></li> </ol><p><a class=\"rated-user user-blue\" href=\"/profile/Shtrix\" title=\"Expert Shtrix\">Shtrix</a> noted that essentially the same solution can be implemented with only a single set.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fcb5cb34164112e0db4b3ef4b921f55df7ffb005.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> Some participants could see the similarities with a problem Ball Machine from BOI 2013, but the solutions to the both problems are quite different.</p><h4><a href=\"/contest/343/problem/E\" title=\"Codeforces Round 200 (Div. 1)\">343E - Pumping Stations</a></h4><p>In this problem we are asked to find such graph vertex permutation that maximizes the sum of the maximum flows sent between each two consequtive vertices in the permutation.</p><p>The problem can be solved with <a href=\"https://en.wikipedia.org/wiki/Gomory%E2%80%93Hu_tree\">Gomory-Hu</a> tree data structure. For a given weighted graph the tree has the following properties:</p> <ol> <li>The vertex set of the tree and the graph is the same.</li> <li>The maximum flow between vertices <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> in the tree is equal to the maximum flow in the graph.</li> </ol><p>Surprisingly, such a tree exists for any weighted graph, and can be built in <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. It appears that the answer to the problem is equal to the sum of the edge weights in this tree.</p><p>We prove this statement by induction on the number of the tree vertices. Pick the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> with the smallest weight in the tree. Consider that in an optimal permutation more than one path between two adjacent verteces in the permutation passes through this edge. Erase all these paths, then each of the <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> subtrees holds a set of disjoint remaining paths from the permutation. For each set, join all the paths in one chain, obtaining two chains. These chains we join by a path <span class=\"tex-span\"><i>s</i></span> that goes trough the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>. Thus we have built a permutation that is not worse than the considered one. For a path <span class=\"tex-span\"><i>s</i></span> the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> is the smallest, so the flow along this path is equal to the weight of this edge. It follows from the induction that in subtrees <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> the answer is equal to the sum of edges. By adding the weight of edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>, we get the desired result.</p><p>From the last paragraph it is clear how to build such a permutation: take the smallest edge, obtain two chains from the vertex subtrees recursively, and add them together to form a one chain. Since there are not many vertices, we can do this part in <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-orange\" href=\"/profile/Gerald\" title=\"Master Gerald\">Gerald</a>.</p><p><strong>Bonus:</strong> Shortly before the contest we decided to make the constraints more loyal, so some solution that find Gomory-Hu tree by finding flow <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> times also passed. We hope that nobody is particularly saddened by this fact. (;</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/343\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/344\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-8915\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"8860\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=200\" class=\"tag notice\" style=\"text-decoration: none;\">200</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+64</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8860#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8860#comments\">\n 53\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8931\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (43)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145823\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bipinb1994\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/91315/avatar/b4e2d8ac5b2569a3.jpg'/> </a>\n <div><a href=\"/profile/bipinb1994\" title=\"Expert bipinb1994\" class=\"rated-user user-blue\">bipinb1994</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 07:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145823\" href=\"?#comment-145823\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145823\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-15\"\r\n data-commentUserId=\"91315\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145823\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hai this was my first round in Codeforces. But my code was not accepted and it says that it was wrong with the 3rd test case. What i did was put a loop from 0 to n-1 and i checked ch[i][!=ch[i+1][0] then count++; else continue where 'ch' is the character array(2-D) whose size was Nx3 ...Is this algorithm completely wrong. As i said this was the first round here i did not understand what is wrong with this. If possible please do tell me what is wrong with this algorithm..:(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145823 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145823 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145823\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145863\" commentParentId=\"145823\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 14:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145863\" href=\"?#comment-145863\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145823\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145863\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145863\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please look at link <a href=\"//codeforces.com/contest/344/submission/4461494\">http://codeforces.com/contest/344/submission/4461494</a>. </p><p>The log says</p><p>Time: 0 ms, memory: 0 KB Verdict: WRONG_ANSWER Input 1 10 Output 0 Answer 1 Checker comment wrong answer 1st numbers differ — expected: '1', found: '0'</p><p>I believe this should be self explanatory. </p><p>Also it would help playing around with the system before trying to enter a rated match.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145863 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145863 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145863\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146026\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ka16\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ka16\" title=\"Pupil ka16\" class=\"rated-user user-green\">ka16</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 06:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146026\" href=\"?#comment-146026\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146026\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"12131\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146026\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody please clarify the two choices of head(s) in the solution of 343C-Read Time problem above? I couldn't understand it completely. Thank in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146026 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146026 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146026\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146037\" commentParentId=\"146026\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hriss95\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27396/avatar/d6cec8eac7bdbde3.jpg'/> </a>\n <div><a href=\"/profile/hriss95\" title=\"Expert hriss95\" class=\"rated-user user-blue\">hriss95</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 13:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146037\" href=\"?#comment-146037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146026\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146037\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"27396\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have to choose one of the two types moving: first to the right or first to the left. You have to use the one which covers more points to the right. Note that both types of moving cover the left point and that's why you have to take as much as points as you can to the right.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146037\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sorin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/sorin\" title=\"Expert sorin\" class=\"rated-user user-blue\">sorin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 12:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146034\" href=\"?#comment-146034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"124904\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody give me a hint for the bonus at Div2 — B? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146034\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146064\" commentParentId=\"146034\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 21:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146064\" href=\"?#comment-146064\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146034\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146064\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146064\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Think greedy ;]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146064 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146064 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146064\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"152157\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ghooo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2010/avatar/659a8aca8b12506a.jpg'/> </a>\n <div><a href=\"/profile/ghooo\" title=\"Master ghooo\" class=\"rated-user user-orange\">ghooo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/26/2013 08:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-152157\" href=\"?#comment-152157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"152157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2010\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-152157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>will the connections between the atoms be circular? like 1 <-> 2 <-> 3 <-> 4 <-> 5 ... n <-> 1 (again) ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-152157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-152157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-152157\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"521750\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/n0tred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1177564/avatar/a46e0281e87dd6c9.jpg'/> </a>\n <div><a href=\"/profile/n0tred\" title=\"Candidate Master n0tred\" class=\"rated-user user-violet\">n0tred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/25/2019 14:29\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-521750\" href=\"?#comment-521750\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"521750\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1177564\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-521750\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you give a better hint? (Maybe through a spoiler, I suppose)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-521750 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-521750 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-521750\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"523308\" commentParentId=\"521750\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/29/2019 09:36\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-523308\" href=\"?#comment-523308\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-521750\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"523308\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-523308\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the algorithm that continuously connects the vertex with the smallest degree with the vertex with the largest degree works (here by degree I mean the unconnected edges), and builds a connected graph. I think this can be proved by induction.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-523308 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-523308 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-523308\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146129\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 11:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146129\" href=\"?#comment-146129\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146129\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146129\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think there is an issue with Problem 343A — Rational Resistance. Here according to the editorial the answer to the ratio 6/5 would be 6(I have verified this with an accepted solution). But this ratio can be achieved with a resistance of 2 and 3 in parallel, which makes the number of resistors required equal to 5 which would imply the editorial and the system tests to be wrong.</p><p>Am I missing something here?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146129 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146129 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146129\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146259\" commentParentId=\"146129\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146259\" href=\"?#comment-146259\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146129\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146259\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146259\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think it's because the definition of <strong>one element</strong> only let you add <strong>one</strong> new unit resistor to another element</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146259 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146259 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146259\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146256\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146256\" href=\"?#comment-146256\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146256\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146256\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for the nice problems!</p><p>I just have a little question on 343C — Read Time. I use the same algorithm and get AC, but my algorithm is running at O(n log^2 n)... as for the step: "Then we move the pointer onto the first unread track" I use another binary search...</p><p>how can I implement the same algorithm with O(n log n) as said in editorial? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146256 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146256 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146256\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146269\" commentParentId=\"146256\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146269\" href=\"?#comment-146269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146256\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146269\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We hold two pointers: the first points at the first unread track from the left, and the second points at the first unused head so far. So we take this head and read with its help the maximum number of yet unread tracks (note that they are consequent and begin at the first pointer) according to the best of the two choices described in tutorial. Then we move the first pointer to the first yet unread track, and increment the second by one. Thus each pointer moves <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> times in this iteration of the binary search. Take also in consideration that some heads can be not used at all.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154161\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/s2k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146708/avatar/ec43946f377e5c64.jpg'/> </a>\n <div><a href=\"/profile/s2k\" title=\"Newbie s2k\" class=\"rated-user user-gray\">s2k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154161\" href=\"?#comment-154161\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154161\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146708\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154161\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi. I was just trying to solve problem A of division 2, but was unsuccessful after hours of effort. I eventually lost patience and decided to see the codes of others. I did understand what was going in the code, but couldn't figure out why this method was chosen in the first place. Can someone please help me understand the solution?</p><p>P.S. I'm a newbie with almost no prior knowledge about number theory. :$</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154161 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154161 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154161\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154163\" commentParentId=\"154161\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154163\" href=\"?#comment-154163\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-154161\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154163\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154163\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The number of islands is always one more than the number of splits between two neighboring dominoes. One can easily convince himself by looking at an image in the description.</p><p>There are 4 possibilities of neighboring dominoes:</p> <ul> <li>01 and 01: these attract, so they don't form a split and we don't care about them</li> <li>10 and 10: these attract, so they don't form a split and we don't care about them</li> <li>01 and 10: these don't attract, so they form a split</li> <li>10 and 01: these don't attract, so they form a split</li> </ul><p>So, we can deduce that we're only interested in neighboring dominoes that are different. This means we can just count the number of indexes i (1 <= i < N) such that s[i] != s[i+1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154163 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154163 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154163\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176652\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/S.Ged\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67184/avatar/a38f51555a40b56a.jpg'/> </a>\n <div><a href=\"/profile/S.Ged\" title=\"Candidate Master S.Ged\" class=\"rated-user user-violet\">S.Ged</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 04:10\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176652\" href=\"?#comment-176652\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"176652\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"176652\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"67184\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176652\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm confused by the first sentence of 343A — Rational Resistance tutorial</p><p>How can we obtain a/(a+b) with k+1 resistors if obatined a/b wiht k resistors ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176652 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176652 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176652\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176656\" commentParentId=\"176652\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/afrizal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/103639/avatar/206f6cf479b00060.jpg'/> </a>\n <div><a href=\"/profile/afrizal\" title=\"Expert afrizal\" class=\"rated-user user-blue\">afrizal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 07:05\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176656\" href=\"?#comment-176656\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176652\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"176656\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"103639\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176656\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Remember a/a is 1. If we have a/b resistance, put one more resistor parallel will give <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c1a16b55f7f10840909e0e5863ae3ce22e36c85b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176656 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176656 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176656\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"189636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/namikaze\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/227989/avatar/51e67e9e139a65f2.jpg'/> </a>\n <div><a href=\"/profile/namikaze\" title=\"Unrated, namikaze\" class=\"rated-user user-black\">namikaze</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/28/2014 15:45\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-189636\" href=\"?#comment-189636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"189636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"227989\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-189636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><code>adding one resistor means performing one operation backwards in Euclidean algorithm</code></p><p>Can someone explain this ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-189636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-189636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-189636\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"277029\" commentParentId=\"189636\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TomBombadil\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/106415/avatar/ed9d8ef375273241.jpg'/> </a>\n <div><a href=\"/profile/TomBombadil\" title=\"Specialist TomBombadil\" class=\"rated-user user-cyan\">TomBombadil</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2016 17:50\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-277029\" href=\"?#comment-277029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-189636\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"277029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"106415\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-277029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-orange\" href=\"/profile/gen\" title=\"Master gen\">gen</a> ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-277029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-277029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-277029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"351231\" commentParentId=\"277029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/R.A.X\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/122476/avatar/686763c746ac6e7b.jpg'/> </a>\n <div><a href=\"/profile/R.A.X\" title=\"Specialist R.A.X\" class=\"rated-user user-cyan\">R.A.X</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/27/2017 15:37\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-351231\" href=\"?#comment-351231\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-277029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"351231\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"351231\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"122476\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-351231\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Suppose you have resistance of(17/3), it could be formed by adding 1 + (14/3). If you have resistance of (3/17), it could be obtained by combining resistance of 1 and 3/14 in parallel.</p><p>In terms of variable, a/b could be obtained by 1 + resistors required to create ( a-b)/b resistance, assuming a>b. and a/b if b>a, could be obtained by 1 + resistors required to create ( a/(b-a) ).</p><p>Assuming a>b so resistorRequired(a,b) = 1 + resistorRequired(a-b,b).</p> <pre>resistorReqiored(a-b,b) = 1 + resistorRequired(a-2b,b)</pre><p>............</p> <pre>resistorRequired(a-(q-1)*b ,b) = 1 + resistorRequired(a-q*b,b)</pre><p>let say r = a-q*b == a%b now at this point, one resistance needs to be connected in parallel to the b/r resistance.</p><p>so again problem becomes calculating the requiredResistance(b,r) similar to above problem,</p><p>which is similar to the gcd problem.</p><p>Hope that helps.</p><p>Why it's like gcd(a,b) = gcd(a-b,b) =gcd(a-2b,b) .... </p><p>In case of gcd(a,b) = gcd(a-b,b)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-351231 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-351231 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-351231\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"393063\" commentParentId=\"351231\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ShafinKhadem\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/508696/avatar/1b5c8ae9cf51dc77.jpg'/> </a>\n <div><a href=\"/profile/ShafinKhadem\" title=\"Master ShafinKhadem\" class=\"rated-user user-orange\">ShafinKhadem</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/01/2017 09:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-393063\" href=\"?#comment-393063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-351231\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"393063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"508696\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-393063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for the nice explanation. Now the use of euclidian algorithm to solve this problem makes sense to me.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-393063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-393063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-393063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"220282\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CloverAsta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207753/avatar/45b71a38344fa830.jpg'/> </a>\n <div><a href=\"/profile/CloverAsta\" title=\"Expert CloverAsta\" class=\"rated-user user-blue\">CloverAsta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/01/2015 14:33\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-220282\" href=\"?#comment-220282\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"220282\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207753\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-220282\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain to me the solution for Problem C div2 I understand the transition from <code>k</code> to <code>k + 1</code> but the part about Euclidean algorithm is beyond me</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-220282 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-220282 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-220282\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"232136\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anajin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221428/avatar/b8f5979933e2ce3d.jpg'/> </a>\n <div><a href=\"/profile/anajin\" title=\"Expert anajin\" class=\"rated-user user-blue\">anajin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/03/2015 14:15\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-232136\" href=\"?#comment-232136\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"232136\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-232136\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>water tree can be solved by heavy-light decomposition...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-232136 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-232136 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-232136\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"454886\" commentParentId=\"232136\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cai_lw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/325977/avatar/202b61935928944.jpg'/> </a>\n <div><a href=\"/profile/cai_lw\" title=\"International Master cai_lw\" class=\"rated-user user-orange\">cai_lw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/30/2018 20:04\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-454886\" href=\"?#comment-454886\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-232136\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"454886\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"454886\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"325977\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-454886\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, this is almost the most standard problem for HLD. But their solution is cleverer and has lower time complexity. HLD is a little bit overkill for such simple operations.</p><p>Nevertheless, HLD can pass the test. My HLD solution passed in 900ms.</p><p>Also HLD was a relatively unknown algorithm to the CP community 5 years ago.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-454886 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-454886 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-454886\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"634570\" commentParentId=\"454886\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Suri429\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/776807/avatar/90399ec92a81320a.jpg'/> </a>\n <div><a href=\"/profile/Suri429\" title=\"Master Suri429\" class=\"rated-user user-orange\">Suri429</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2020 08:55\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-634570\" href=\"?#comment-634570\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-454886\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"634570\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"776807\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-634570\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain how to approach this with HLD? I am new to HLD, and not able to get any clue here. </p><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-634570 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-634570 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-634570\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"312598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/29/2016 12:31\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-312598\" href=\"?#comment-312598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"312598\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"312598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-312598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder why I did wrong in the implementation of lazy propagation for Div1D, could anyone kindly lend some help? </p><p><a href=\"//codeforces.com/contest/343/submission/20226349\">http://codeforces.com/contest/343/submission/20226349</a></p><p>Thanks in advance. =)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-312598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-312598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-312598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"357445\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anshulgarg19\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/anshulgarg19\" title=\"Pupil anshulgarg19\" class=\"rated-user user-green\">anshulgarg19</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/02/2017 20:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-357445\" href=\"?#comment-357445\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"357445\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"244328\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-357445\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Accepted solution for the problem 343A Rational Resistance would give 6 as the output for input a = 10 and b = 7 i.e.10/7. But, if we have 5 ohm and 2 ohm resistors in parallel, then we have the same resistance value 10/7. So minimum value should be 2 resistors for this case. Kindly explain if i am wrong in understanding the problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-357445 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-357445 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-357445\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360009\" commentParentId=\"357445\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/snehil10\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/351506/avatar/522f61633a219a3b.jpg'/> </a>\n <div><a href=\"/profile/snehil10\" title=\"Expert snehil10\" class=\"rated-user user-blue\">snehil10</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/14/2017 10:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360009\" href=\"?#comment-360009\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-357445\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"360009\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"351506\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360009\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have only 1-ohm resistors in the beginning. Thus it requires 5 1-ohm resistors to make a 5-ohm resistor, and 2 1-ohm resistors to make a 2-ohm resistor. So according to you answer is 7 and not 2.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360009 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360009 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360009\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371475\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rush_123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/rush_123\" title=\"Expert rush_123\" class=\"rated-user user-blue\">rush_123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/03/2017 17:42\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371475\" href=\"?#comment-371475\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"371475\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"439840\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371475\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 343D — Water Tree query 1 and 2 can be solved using a dfs to find in time and out time for every node and then using segment tree But what about 3rd query how to solve it?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371475 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371475 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371475\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"422269\" commentParentId=\"371475\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stringray\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/575608/avatar/2902babcf56868a2.jpg'/> </a>\n <div><a href=\"/profile/stringray\" title=\"Expert stringray\" class=\"rated-user user-blue\">stringray</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/28/2018 16:13\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-422269\" href=\"?#comment-422269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371475\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"422269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"575608\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-422269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yeah same question .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-422269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-422269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-422269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"437012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ragnarok_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ragnarok_\" title=\"Newbie ragnarok_\" class=\"rated-user user-gray\">ragnarok_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2018 08:59\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-437012\" href=\"?#comment-437012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"437012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"673189\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-437012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Q.343A can anybody explain me why min resistor for 199/200 is 200.....it can be also constructed using 101 resistors(1/2+1/4+1/5+1/40+1/50)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-437012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-437012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-437012\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"573631\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SLIMSHADYNICK\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/598862/avatar/7629f1b29f0fe807.jpg'/> </a>\n <div><a href=\"/profile/SLIMSHADYNICK\" title=\"Candidate Master SLIMSHADYNICK\" class=\"rated-user user-violet\">SLIMSHADYNICK</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2020 21:03\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-573631\" href=\"?#comment-573631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"573631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"598862\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-573631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>correct!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-573631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-573631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-573631\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587715\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pied-piper\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/754580/avatar/a6fb81d49bb96665.jpg'/> </a>\n <div><a href=\"/profile/pied-piper\" title=\"Expert pied-piper\" class=\"rated-user user-blue\">pied-piper</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/11/2020 16:14\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587715\" href=\"?#comment-587715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"587715\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"587715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"754580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It is because they are separate elements and hence they cannot be added together. Only an element and a 1 unit resistance can be added in series(or parallel)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587715\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"791297\" commentParentId=\"587715\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/15/2021 17:25\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-791297\" href=\"?#comment-791297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587715\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"791297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-791297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-791297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-791297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-791297\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"598229\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayank_ag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/644568/avatar/c1136e364e721d18.jpg'/> </a>\n <div><a href=\"/profile/mayank_ag\" title=\"Master mayank_ag\" class=\"rated-user user-orange\">mayank_ag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/05/2020 20:53\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-598229\" href=\"?#comment-598229\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"598229\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"644568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-598229\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>An alternate approach for solving D: Use of lazy segment tree over HLD & Euler path. For every filling, fill Euler path with current query number, and for emptying, fill HLD path from the root with query number. For queries, check which of the seg tree has high query number.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-598229 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-598229 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-598229\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"600816\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Asterix_11\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Asterix_11\" title=\"Pupil Asterix_11\" class=\"rated-user user-green\">Asterix_11</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/11/2020 00:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-600816\" href=\"?#comment-600816\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"600816\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1472760\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-600816\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem 344A</p> <pre><code>#include <iostream>\nusing namespace std;\nint main()\n{\n int a, i, b[100], ans;\n scanf("%d", &a);\n for(i = 0; i < a; ++i){\n scanf("%d", &b[i]);\n }\n ans = 1;\n for(i = 0; i < (a-1); ++i){\n if(b[i] != b[i + 1]){\n ++ans;}\n }\n printf("%d", ans);\n return 0;\n}\n</code></pre><p>This is my code, but I don't know how to improve it, so that the time limit won't be a problem anymore. Any help?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-600816 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-600816 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-600816\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752098\" commentParentId=\"600816\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 09:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752098\" href=\"?#comment-752098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-600816\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can make two variable for prev and current value and if they are not equal you can increment it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752098\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752075\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:25\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752075\" href=\"?#comment-752075\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752075\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752075\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Problem C, if more than one of the elements can be in parallel than for ratio 199 and 200 the answer given is 200. But we may solve this in 74. like 1/2+1/4+1/8+1/10+1/50.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752075 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752075 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752075\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752089\" commentParentId=\"752075\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752089\" href=\"?#comment-752089\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-752075\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752089\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752089\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Okay it would be like either + denominator to the numerator or + numerator to the denominator.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752089 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752089 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752089\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"946539\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mohsina_Shaikh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1396580/avatar/6f21616a2d8d578.jpg'/> </a>\n <div><a href=\"/profile/Mohsina_Shaikh\" title=\"Newbie Mohsina_Shaikh\" class=\"rated-user user-gray\">Mohsina_Shaikh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/24/2022 06:47\">13 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-946539\" href=\"?#comment-946539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"946539\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"946539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1396580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-946539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a> or <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a> or can anyone please explain <code>Alternating Current</code> Solution.Tried so hard but not able to understand it. A</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-946539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-946539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-946539\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"959164\" commentParentId=\"946539\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rishijoshi483\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2453886/avatar/1ecf48b346fe39d0.jpg'/> </a>\n <div><a href=\"/profile/rishijoshi483\" title=\"Expert rishijoshi483\" class=\"rated-user user-blue\">rishijoshi483</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/03/2022 09:44\">12 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-959164\" href=\"?#comment-959164\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-946539\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"959164\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2453886\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-959164\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try it using stack</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-959164 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-959164 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-959164\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"966651\" commentParentId=\"959164\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Yohajji\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2854745/avatar/b31d6e4c63852741.jpg'/> </a>\n <div><a href=\"/profile/Yohajji\" title=\"Newbie Yohajji\" class=\"rated-user user-gray\">Yohajji</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2022 13:35\">11 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-966651\" href=\"?#comment-966651\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-959164\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"966651\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2854745\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-966651\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>using the stack was a brilliant aproach, thank you </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-966651 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-966651 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-966651\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1039007\" commentParentId=\"966651\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AbdelrahmanMahallawy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3189297/avatar/6b2a1658ad37caa0.jpg'/> </a>\n <div><a href=\"/profile/AbdelrahmanMahallawy\" title=\"Newbie AbdelrahmanMahallawy\" class=\"rated-user user-gray\">AbdelrahmanMahallawy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/20/2023 03:36\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1039007\" href=\"?#comment-1039007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-966651\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1039007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3189297\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1039007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>anytime </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1039007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1039007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1039007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8931\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8931 = true;\r\nvar lastPreviewContent8931 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8931] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8931] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:23</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128748fcb8816ab',t:'MTY5NjcwNTk0My4yOTkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1746,"cells":{"problem_id":{"kind":"string","value":"344E"},"contest":{"kind":"string","value":"344"},"problem":{"kind":"string","value":"E"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"E. Read Time"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Read Time</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike does not use slow hard disks. His modification of a hard drive has not one, but <span class=\"tex-span\"><i>n</i></span> different heads that can read data in parallel.</p><p>When viewed from the side, Mike's hard drive is an endless array of tracks. The tracks of the array are numbered from left to right with integers, starting with 1. In the initial state the <span class=\"tex-span\"><i>i</i></span>-th reading head is above the track number <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span>. For each of the reading heads, the hard drive's firmware can move the head exactly one track to the right or to the left, or leave it on the current track. During the operation each head's movement does not affect the movement of the other heads: the heads can change their relative order; there can be multiple reading heads above any of the tracks. A track is considered <span class=\"tex-font-style-underline\">read</span> if at least one head has visited this track. In particular, all of the tracks numbered <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>n</i></sub></span> have been read at the beginning of the operation.</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/74f1fe19c026065f690c4ac1646b3951b4afb6ea.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>Mike needs to read the data on <span class=\"tex-span\"><i>m</i></span> distinct tracks with numbers <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>m</i></sub></span>. Determine the minimum time the hard drive firmware needs to move the heads and read all the given tracks. Note that an arbitrary number of other tracks can also be read.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains two space-separated integers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i>, <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup></span>) — the number of disk heads and the number of tracks to read, accordingly. The second line contains <span class=\"tex-span\"><i>n</i></span> distinct integers <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span> in ascending order (<span class=\"tex-span\">1 ≤ <i>h</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">10</sup></span>, <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub> < <i>h</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>) — the initial positions of the heads. The third line contains <span class=\"tex-span\"><i>m</i></span> distinct integers <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> in ascending order (<span class=\"tex-span\">1 ≤ <i>p</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">10</sup></span>, <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub> < <i>p</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>) - the numbers of tracks to read.</p><p>Please, do not use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in С++. It is recommended to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single number — the minimum time required, in seconds, to read all the needed tracks.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 4<br/>2 5 6<br/>1 3 6 8<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>1 2 3<br/>1 2 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 2<br/>165<br/>142 200<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>81<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The first test coincides with the figure. In this case the given tracks can be read in 2 seconds in the following way: </p><ol> <li> during the first second move the 1-st head to the left and let it stay there; </li><li> move the second head to the left twice; </li><li> move the third head to the right twice (note that the 6-th track has already been read at the beginning). </li></ol><p>One cannot read the tracks in 1 second as the 3-rd head is at distance 2 from the 8-th track.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"1d8eb48788e8579c6e12182206761d85\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"97388d8e9a3336f0fbcbc9a7e735a42b6679436b\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='1d8eb48788e8579c6e12182206761d85'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F344%2Fproblem%2FE%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='1d8eb48788e8579c6e12182206761d85'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/344\">Codeforces Round 200 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='1d8eb48788e8579c6e12182206761d85'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/344/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Binary search\">\r\n binary search\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Two pointers\">\r\n two pointers\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1900\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='1d8eb48788e8579c6e12182206761d85'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3466\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='1d8eb48788e8579c6e12182206761d85'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3466\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8851\" title=\"Codeforces Round #200\" target=\"_blank\">Codeforces Round #200</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1854:1855\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8860\" title=\"Codeforces Round #200 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1850:1851\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/344\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/344/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/344/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/344/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/344/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/344/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/344/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/344/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_bfe7781f3a2e066673494b742533c5c872b2493b\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Read Time</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Mad scientist Mike does not use slow hard disks. His modification of a hard drive has not one, but <span class=\"tex-span\"><i>n</i></span> different heads that can read data in parallel.</p><p>When viewed from the side, Mike's hard drive is an endless array of tracks. The tracks of the array are numbered from left to right with integers, starting with 1. In the initial state the <span class=\"tex-span\"><i>i</i></span>-th reading head is above the track number <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span>. For each of the reading heads, the hard drive's firmware can move the head exactly one track to the right or to the left, or leave it on the current track. During the operation each head's movement does not affect the movement of the other heads: the heads can change their relative order; there can be multiple reading heads above any of the tracks. A track is considered <span class=\"tex-font-style-underline\">read</span> if at least one head has visited this track. In particular, all of the tracks numbered <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>n</i></sub></span> have been read at the beginning of the operation.</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/74f1fe19c026065f690c4ac1646b3951b4afb6ea.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>Mike needs to read the data on <span class=\"tex-span\"><i>m</i></span> distinct tracks with numbers <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>m</i></sub></span>. Determine the minimum time the hard drive firmware needs to move the heads and read all the given tracks. Note that an arbitrary number of other tracks can also be read.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains two space-separated integers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i>, <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup></span>) — the number of disk heads and the number of tracks to read, accordingly. The second line contains <span class=\"tex-span\"><i>n</i></span> distinct integers <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span> in ascending order (<span class=\"tex-span\">1 ≤ <i>h</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">10</sup></span>, <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub> < <i>h</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>) — the initial positions of the heads. The third line contains <span class=\"tex-span\"><i>m</i></span> distinct integers <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> in ascending order (<span class=\"tex-span\">1 ≤ <i>p</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">10</sup></span>, <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub> < <i>p</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>) - the numbers of tracks to read.</p><p>Please, do not use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in С++. It is recommended to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single number — the minimum time required, in seconds, to read all the needed tracks.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 4<br />2 5 6<br />1 3 6 8<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />1 2 3<br />1 2 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 2<br />165<br />142 200<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>81<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The first test coincides with the figure. In this case the given tracks can be read in 2 seconds in the following way: </p><ol> <li> during the first second move the 1-st head to the left and let it stay there; </li><li> move the second head to the left twice; </li><li> move the third head to the right twice (note that the 6-th track has already been read at the beginning). </li></ol><p>One cannot read the tracks in 1 second as the 3-rd head is at distance 2 from the 8-th track.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:45</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bdba8e679d9c',t:'MTY5NjY0NjAyNS40MjQwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Binary search\", \"Two pointers\"]"},"short_tags":{"kind":"string","value":"[\"binary search\", \"two pointers\", \"*1900\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8860"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"21ba25574a0615e5dc71db6e32a512d8\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #200 Tutorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #200 Tutorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='21ba25574a0615e5dc71db6e32a512d8'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8860\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:38</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='21ba25574a0615e5dc71db6e32a512d8'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/gen\">gen</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gen\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gen\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gen\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gen\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gen\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gen\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gen\" style=\"text-decoration:none;color:black !important;\">gen's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8915\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8860\"> <p>Codeforces Round #200 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a>,\r\n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h4><a href=\"/contest/344/problem/A\" title=\"Codeforces Round 200 (Div. 2)\">344A - Magnets</a></h4><p>By the definition each block consists of a number of consequent and equally oriented dominoes. That means that in places where adjacent dominoes are not oriented equally, one block ends and another block starts. So, if there are <span class=\"tex-span\"><i>x</i></span> such places, the answer is equal to <span class=\"tex-span\"><i>x</i> + 1</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> The problem was created a day before the contest and filled in the last part of a physically flavoured DivII complect. :]</p><h4><a href=\"/contest/344/problem/B\" title=\"Codeforces Round 200 (Div. 2)\">344B - Simple Molecules</a></h4><p>First solution. First, the sum <span class=\"tex-span\"><i>a</i> + <i>b</i> + <i>c</i></span> should be even, since each bond adds 2 to the sum. Now let <span class=\"tex-span\"><i>x</i></span>, <span class=\"tex-span\"><i>y</i></span>, <span class=\"tex-span\"><i>z</i></span> be the number of bonds between 1st and 2nd, 2nd and 3rd, 3rd and 1st atoms, accordingly. So we have to solve the system <span class=\"tex-span\"><i>x</i> + <i>z</i> = <i>a</i></span>, <span class=\"tex-span\"><i>y</i> + <i>x</i> = <i>b</i></span>, <span class=\"tex-span\"><i>z</i> + <i>y</i> = <i>c</i></span>. Now observe that the solution to the system is the length of the tangents on the triangle with sides of length <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span> to its inscribed circle, and are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/2cee22ffa44dda3ce1b315e8cceef38c6288cf2c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1aed1c363b13d01e1b412b9cd3d5e34d19eb9c96.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/30fbfc651674588cadbee1fedd1e4b0d08d1ad4e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. If the problem asked only the possibility of building such a molecule, we could just check if there exists (possibly degenerate) triangle with sides <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span>.</p><p><img alt=\" \" src=\"/predownloaded/e3/d3/e3d3c930f4f93ca68c1e61630a2771472ecbd60a.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Second solution. Bruteforce all <span class=\"tex-span\"><i>x</i></span> values. For a fixed <span class=\"tex-span\"><i>x</i></span> values of <span class=\"tex-span\"><i>y</i></span> and <span class=\"tex-span\"><i>z</i></span> are defined uniquely: <span class=\"tex-span\"><i>y</i> = <i>b</i> - <i>x</i></span>, <span class=\"tex-span\"><i>z</i> = <i>a</i> - <i>x</i></span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(1) / <i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> Can you solve the problem for any vertex number <span class=\"tex-span\"><i>n</i></span>? When and how can such a graph be built?</p><h4><a href=\"/contest/343/problem/A\" title=\"Codeforces Round 200 (Div. 1)\">343A - Rational Resistance</a></h4><p>If a fraction <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58deb68a92272d09bf8f758a3c1e806b2e2c92b5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> can be obtained with <span class=\"tex-span\"><i>k</i></span> resistors, then it is simple to calculate that we can obtain fractions <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b6913fd8136f518e8a7898a9b759b74c4d483101.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/daf9572f0aa7677d7961c329e6277818df63bd9f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> with <span class=\"tex-span\"><i>k</i> + 1</span> resistors. So adding one resistor means performing one operation backwards in Euclidean algorithm. That means that the answer is equal to the number of steps in standard Euclidean algorithm.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e847ae811adbd761fa24db4ba7a6827e0806d670.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Бонус:</strong> At first we thought about the major problem (any two elements can be joined), but had a moment of eureka and got that the given problem unexpectedly naturally can be reduced to GCD. By the way, the result tree — <a href=\"https://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree\">http://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree</a>.</p><h4><a href=\"/contest/343/problem/B\" title=\"Codeforces Round 200 (Div. 1)\">343B - Alternating Current</a></h4><p>Let us solve the following problem first: we are given a string of symbols A and B. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>A</i></span>, then at the <span class=\"tex-span\"><i>i</i></span>-th step the upper wire (see figure) is being put over the lower wire. If the <span class=\"tex-span\"><i>i</i></span>-th symbol is <span class=\"tex-span\"><i>B</i></span>, the lower wire is being put over the upper wire at <span class=\"tex-span\"><i>i</i></span>-th step. Observe that if some two symbols <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are adjacent, we can untangle this place, throw the symbols out and obtain the string of length two symbols less. So the wires can be untangled iff the number of A's and B's in the string is the same. The given problem can be reduced to the described in a following fashion: in each odd position we change – to B and + to A. In each even position we change — to A and + to B. The reduction is correct, since on each even position the order of — and + are always swapped, and in each odd position their order is the same as in the beginning.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a>.</p><p><strong>Bonus:</strong> If you are interested by this problem, you can learn about the braid theory <a href=\"https://en.wikipedia.org/wiki/Braid_theory\">http://en.wikipedia.org/wiki/Braid_theory</a> :] Fun fact: a harder version of this problem was planned already for Round #142, but the error in solution idea was found, and the problem was left to lay for almost a year.</p><h4><a href=\"/contest/343/problem/C\" title=\"Codeforces Round 200 (Div. 1)\">343C - Read Time</a></h4><p>Let's search the answer <span class=\"tex-span\"><i>t</i></span> with the binary search. Fix some value of <span class=\"tex-span\"><i>t</i></span>. Look at the first head from the left <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> that can read track <span class=\"tex-span\"><i>p</i>[0]</span>. If <span class=\"tex-span\"><i>p</i>[0] > <i>h</i>[<i>i</i>]</span>, then <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> goes to the right <span class=\"tex-span\"><i>t</i></span> seconds and reads all tracks on its way. Otherwise if <span class=\"tex-span\"><i>p</i>[0] ≤ <i>h</i>[<i>i</i>]</span>, then the head has two choices:</p> <ol> <li>go to the right <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> seconds, then <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d14b30f572927ca6fa00f2ff760e9149e4aa9a7a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> to the left and <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> again to the left;</li> <li>go to the left <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> seconds, then <span class=\"tex-span\"><i>h</i>[<i>i</i>] - <i>p</i>[0]</span> to the right and <span class=\"tex-span\"><i>t</i> - 2·(<i>h</i>[<i>i</i>] - <i>p</i>[0])</span> again to the right.</li> </ol><p>Obviously, for <span class=\"tex-span\"><i>h</i>[<i>i</i>]</span> it is more advantageous to visit the track positioned as much as possible to the right. So we choose by <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7edc4f5554e1d173945160b7deaca92e61d7a755.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Then we move the pointer onto the first unread track, and repeat the algorithm for <span class=\"tex-span\"><i>h</i>[<i>i</i> + 1]</span>, and so on with each head.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/3342f24e1fd6ab939313f6d6278245c95d89544f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a>.</p><p><strong>Bonus:</strong> The problem is completely real, if the disk has only a single head, if we know, what tracks should be read; then the optimal algorithm chooses between the two choices described above. I and <a class=\"rated-user user-green\" href=\"/profile/gorbunov\" title=\"Pupil gorbunov\">gorbunov</a> were listening this on a lecture, and created the given problem out of boredom ;]</p><h4><a href=\"/contest/343/problem/D\" title=\"Codeforces Round 200 (Div. 1)\">343D - Water Tree</a></h4><p>Let's learn how to color a whole subtree. For that enumerate all vertices in post-order DFS. Then each subtree covers a single continious vertex number segment. For each vertex we store the bounds of such segment for a subtree with a root in this vertex. Then to color a subtree means to color a segment in a segment tree.</p><p>Then create a segment tree that has a following property: if a vertex <span class=\"tex-span\"><i>v</i></span> was emptied, and is still empty, then this vertex is colored in the segment tree. In the beginning "empty" all the vertices. That is, color all the vertices in the segment tree. With this tree we can efficiently process the queries:</p> <ol> <li><p>Fill a vertex <span class=\"tex-span\"><i>v</i></span>. Clean the interval for the subtree of <span class=\"tex-span\"><i>v</i></span>. If before that some vertex of a subtree was empty, color the parent of <span class=\"tex-span\"><i>v</i></span>.</p></li> <li><p>Empty a vertex <span class=\"tex-span\"><i>v</i></span>. Color the vertex <span class=\"tex-span\"><i>v</i></span> in the segment tree.</p></li> <li><p>Reply whether a vertex <span class=\"tex-span\"><i>v</i></span> is filled. If in the segment tree at least one vertex is colored, then there is such a descendant of <span class=\"tex-span\"><i>v</i></span> that is empty now, so the vertex <span class=\"tex-span\"><i>v</i></span> is not filled.</p></li> </ol><p><a class=\"rated-user user-blue\" href=\"/profile/Shtrix\" title=\"Expert Shtrix\">Shtrix</a> noted that essentially the same solution can be implemented with only a single set.</p><p>Solution complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fcb5cb34164112e0db4b3ef4b921f55df7ffb005.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Problem author: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>.</p><p><strong>Bonus:</strong> Some participants could see the similarities with a problem Ball Machine from BOI 2013, but the solutions to the both problems are quite different.</p><h4><a href=\"/contest/343/problem/E\" title=\"Codeforces Round 200 (Div. 1)\">343E - Pumping Stations</a></h4><p>In this problem we are asked to find such graph vertex permutation that maximizes the sum of the maximum flows sent between each two consequtive vertices in the permutation.</p><p>The problem can be solved with <a href=\"https://en.wikipedia.org/wiki/Gomory%E2%80%93Hu_tree\">Gomory-Hu</a> tree data structure. For a given weighted graph the tree has the following properties:</p> <ol> <li>The vertex set of the tree and the graph is the same.</li> <li>The maximum flow between vertices <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> in the tree is equal to the maximum flow in the graph.</li> </ol><p>Surprisingly, such a tree exists for any weighted graph, and can be built in <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. It appears that the answer to the problem is equal to the sum of the edge weights in this tree.</p><p>We prove this statement by induction on the number of the tree vertices. Pick the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> with the smallest weight in the tree. Consider that in an optimal permutation more than one path between two adjacent verteces in the permutation passes through this edge. Erase all these paths, then each of the <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> subtrees holds a set of disjoint remaining paths from the permutation. For each set, join all the paths in one chain, obtaining two chains. These chains we join by a path <span class=\"tex-span\"><i>s</i></span> that goes trough the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>. Thus we have built a permutation that is not worse than the considered one. For a path <span class=\"tex-span\"><i>s</i></span> the edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> is the smallest, so the flow along this path is equal to the weight of this edge. It follows from the induction that in subtrees <span class=\"tex-span\"><i>u</i></span> and <span class=\"tex-span\"><i>v</i></span> the answer is equal to the sum of edges. By adding the weight of edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span>, we get the desired result.</p><p>From the last paragraph it is clear how to build such a permutation: take the smallest edge, obtain two chains from the vertex subtrees recursively, and add them together to form a one chain. Since there are not many vertices, we can do this part in <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span>.</p><p>Solution complexity: <span class=\"tex-span\"><i>O</i>(<i>n</i>·<i>maxFlow</i>)</span>. Problem authors: <a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a>, <a class=\"rated-user user-orange\" href=\"/profile/Gerald\" title=\"Master Gerald\">Gerald</a>.</p><p><strong>Bonus:</strong> Shortly before the contest we decided to make the constraints more loyal, so some solution that find Gomory-Hu tree by finding flow <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> times also passed. We hope that nobody is particularly saddened by this fact. (;</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/343\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/344\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 200 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-8915\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"8860\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=200\" class=\"tag notice\" style=\"text-decoration: none;\">200</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+64</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8915\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/14/2013 21:59\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8860#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8860#comments\">\n 53\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8931\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (43)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145823\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bipinb1994\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/91315/avatar/b4e2d8ac5b2569a3.jpg'/> </a>\n <div><a href=\"/profile/bipinb1994\" title=\"Expert bipinb1994\" class=\"rated-user user-blue\">bipinb1994</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 07:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145823\" href=\"?#comment-145823\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145823\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-15\"\r\n data-commentUserId=\"91315\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145823\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hai this was my first round in Codeforces. But my code was not accepted and it says that it was wrong with the 3rd test case. What i did was put a loop from 0 to n-1 and i checked ch[i][!=ch[i+1][0] then count++; else continue where 'ch' is the character array(2-D) whose size was Nx3 ...Is this algorithm completely wrong. As i said this was the first round here i did not understand what is wrong with this. If possible please do tell me what is wrong with this algorithm..:(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145823 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145823 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145823\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"145863\" commentParentId=\"145823\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/15/2013 14:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-145863\" href=\"?#comment-145863\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-145823\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"145863\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-145863\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please look at link <a href=\"//codeforces.com/contest/344/submission/4461494\">http://codeforces.com/contest/344/submission/4461494</a>. </p><p>The log says</p><p>Time: 0 ms, memory: 0 KB Verdict: WRONG_ANSWER Input 1 10 Output 0 Answer 1 Checker comment wrong answer 1st numbers differ — expected: '1', found: '0'</p><p>I believe this should be self explanatory. </p><p>Also it would help playing around with the system before trying to enter a rated match.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-145863 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-145863 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-145863\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146026\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ka16\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ka16\" title=\"Pupil ka16\" class=\"rated-user user-green\">ka16</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 06:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146026\" href=\"?#comment-146026\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146026\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"12131\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146026\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody please clarify the two choices of head(s) in the solution of 343C-Read Time problem above? I couldn't understand it completely. Thank in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146026 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146026 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146026\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146037\" commentParentId=\"146026\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hriss95\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27396/avatar/d6cec8eac7bdbde3.jpg'/> </a>\n <div><a href=\"/profile/hriss95\" title=\"Expert hriss95\" class=\"rated-user user-blue\">hriss95</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 13:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146037\" href=\"?#comment-146037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146026\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146037\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"27396\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have to choose one of the two types moving: first to the right or first to the left. You have to use the one which covers more points to the right. Note that both types of moving cover the left point and that's why you have to take as much as points as you can to the right.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146037\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sorin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/sorin\" title=\"Expert sorin\" class=\"rated-user user-blue\">sorin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 12:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146034\" href=\"?#comment-146034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"124904\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could somebody give me a hint for the bonus at Div2 — B? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146034\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146064\" commentParentId=\"146034\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2013 21:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146064\" href=\"?#comment-146064\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146034\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146064\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146064\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Think greedy ;]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146064 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146064 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146064\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"152157\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ghooo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2010/avatar/659a8aca8b12506a.jpg'/> </a>\n <div><a href=\"/profile/ghooo\" title=\"Master ghooo\" class=\"rated-user user-orange\">ghooo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/26/2013 08:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-152157\" href=\"?#comment-152157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"152157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2010\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-152157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>will the connections between the atoms be circular? like 1 <-> 2 <-> 3 <-> 4 <-> 5 ... n <-> 1 (again) ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-152157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-152157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-152157\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"521750\" commentParentId=\"146064\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/n0tred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1177564/avatar/a46e0281e87dd6c9.jpg'/> </a>\n <div><a href=\"/profile/n0tred\" title=\"Candidate Master n0tred\" class=\"rated-user user-violet\">n0tred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/25/2019 14:29\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-521750\" href=\"?#comment-521750\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146064\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"521750\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1177564\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-521750\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you give a better hint? (Maybe through a spoiler, I suppose)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-521750 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-521750 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-521750\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"523308\" commentParentId=\"521750\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/29/2019 09:36\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-523308\" href=\"?#comment-523308\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-521750\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"523308\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-523308\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the algorithm that continuously connects the vertex with the smallest degree with the vertex with the largest degree works (here by degree I mean the unconnected edges), and builds a connected graph. I think this can be proved by induction.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-523308 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-523308 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-523308\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146129\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityavikram\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityavikram\" title=\"Expert adityavikram\" class=\"rated-user user-blue\">adityavikram</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2013 11:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146129\" href=\"?#comment-146129\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146129\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"72254\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146129\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think there is an issue with Problem 343A — Rational Resistance. Here according to the editorial the answer to the ratio 6/5 would be 6(I have verified this with an accepted solution). But this ratio can be achieved with a resistance of 2 and 3 in parallel, which makes the number of resistors required equal to 5 which would imply the editorial and the system tests to be wrong.</p><p>Am I missing something here?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146129 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146129 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146129\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146259\" commentParentId=\"146129\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146259\" href=\"?#comment-146259\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146129\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146259\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146259\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think it's because the definition of <strong>one element</strong> only let you add <strong>one</strong> new unit resistor to another element</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146259 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146259 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146259\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146256\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kirakira\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6397/avatar/72fc32de67c72324.jpg'/> </a>\n <div><a href=\"/profile/kirakira\" title=\"Expert kirakira\" class=\"rated-user user-blue\">kirakira</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146256\" href=\"?#comment-146256\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146256\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"6397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146256\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for the nice problems!</p><p>I just have a little question on 343C — Read Time. I use the same algorithm and get AC, but my algorithm is running at O(n log^2 n)... as for the step: "Then we move the pointer onto the first unread track" I use another binary search...</p><p>how can I implement the same algorithm with O(n log n) as said in editorial? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146256 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146256 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146256\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146269\" commentParentId=\"146256\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/20/2013 22:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146269\" href=\"?#comment-146269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146256\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146269\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We hold two pointers: the first points at the first unread track from the left, and the second points at the first unused head so far. So we take this head and read with its help the maximum number of yet unread tracks (note that they are consequent and begin at the first pointer) according to the best of the two choices described in tutorial. Then we move the first pointer to the first yet unread track, and increment the second by one. Thus each pointer moves <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> times in this iteration of the binary search. Take also in consideration that some heads can be not used at all.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154161\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/s2k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146708/avatar/ec43946f377e5c64.jpg'/> </a>\n <div><a href=\"/profile/s2k\" title=\"Newbie s2k\" class=\"rated-user user-gray\">s2k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154161\" href=\"?#comment-154161\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154161\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146708\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154161\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi. I was just trying to solve problem A of division 2, but was unsuccessful after hours of effort. I eventually lost patience and decided to see the codes of others. I did understand what was going in the code, but couldn't figure out why this method was chosen in the first place. Can someone please help me understand the solution?</p><p>P.S. I'm a newbie with almost no prior knowledge about number theory. :$</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154161 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154161 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154161\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"154163\" commentParentId=\"154161\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/15/2013 00:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-154163\" href=\"?#comment-154163\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-154161\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"154163\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-154163\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The number of islands is always one more than the number of splits between two neighboring dominoes. One can easily convince himself by looking at an image in the description.</p><p>There are 4 possibilities of neighboring dominoes:</p> <ul> <li>01 and 01: these attract, so they don't form a split and we don't care about them</li> <li>10 and 10: these attract, so they don't form a split and we don't care about them</li> <li>01 and 10: these don't attract, so they form a split</li> <li>10 and 01: these don't attract, so they form a split</li> </ul><p>So, we can deduce that we're only interested in neighboring dominoes that are different. This means we can just count the number of indexes i (1 <= i < N) such that s[i] != s[i+1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-154163 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-154163 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-154163\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176652\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/S.Ged\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67184/avatar/a38f51555a40b56a.jpg'/> </a>\n <div><a href=\"/profile/S.Ged\" title=\"Candidate Master S.Ged\" class=\"rated-user user-violet\">S.Ged</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 04:10\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176652\" href=\"?#comment-176652\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"176652\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"176652\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"67184\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176652\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm confused by the first sentence of 343A — Rational Resistance tutorial</p><p>How can we obtain a/(a+b) with k+1 resistors if obatined a/b wiht k resistors ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176652 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176652 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176652\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"176656\" commentParentId=\"176652\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/afrizal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/103639/avatar/206f6cf479b00060.jpg'/> </a>\n <div><a href=\"/profile/afrizal\" title=\"Expert afrizal\" class=\"rated-user user-blue\">afrizal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2014 07:05\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-176656\" href=\"?#comment-176656\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-176652\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"176656\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"103639\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-176656\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Remember a/a is 1. If we have a/b resistance, put one more resistor parallel will give <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c1a16b55f7f10840909e0e5863ae3ce22e36c85b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-176656 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-176656 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-176656\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"189636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/namikaze\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/227989/avatar/51e67e9e139a65f2.jpg'/> </a>\n <div><a href=\"/profile/namikaze\" title=\"Unrated, namikaze\" class=\"rated-user user-black\">namikaze</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/28/2014 15:45\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-189636\" href=\"?#comment-189636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"189636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"227989\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-189636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><code>adding one resistor means performing one operation backwards in Euclidean algorithm</code></p><p>Can someone explain this ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-189636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-189636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-189636\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"277029\" commentParentId=\"189636\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TomBombadil\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/106415/avatar/ed9d8ef375273241.jpg'/> </a>\n <div><a href=\"/profile/TomBombadil\" title=\"Specialist TomBombadil\" class=\"rated-user user-cyan\">TomBombadil</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2016 17:50\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-277029\" href=\"?#comment-277029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-189636\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"277029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"106415\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-277029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-orange\" href=\"/profile/gen\" title=\"Master gen\">gen</a> ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-277029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-277029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-277029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"351231\" commentParentId=\"277029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/R.A.X\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/122476/avatar/686763c746ac6e7b.jpg'/> </a>\n <div><a href=\"/profile/R.A.X\" title=\"Specialist R.A.X\" class=\"rated-user user-cyan\">R.A.X</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/27/2017 15:37\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-351231\" href=\"?#comment-351231\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-277029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"351231\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"351231\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"122476\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-351231\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Suppose you have resistance of(17/3), it could be formed by adding 1 + (14/3). If you have resistance of (3/17), it could be obtained by combining resistance of 1 and 3/14 in parallel.</p><p>In terms of variable, a/b could be obtained by 1 + resistors required to create ( a-b)/b resistance, assuming a>b. and a/b if b>a, could be obtained by 1 + resistors required to create ( a/(b-a) ).</p><p>Assuming a>b so resistorRequired(a,b) = 1 + resistorRequired(a-b,b).</p> <pre>resistorReqiored(a-b,b) = 1 + resistorRequired(a-2b,b)</pre><p>............</p> <pre>resistorRequired(a-(q-1)*b ,b) = 1 + resistorRequired(a-q*b,b)</pre><p>let say r = a-q*b == a%b now at this point, one resistance needs to be connected in parallel to the b/r resistance.</p><p>so again problem becomes calculating the requiredResistance(b,r) similar to above problem,</p><p>which is similar to the gcd problem.</p><p>Hope that helps.</p><p>Why it's like gcd(a,b) = gcd(a-b,b) =gcd(a-2b,b) .... </p><p>In case of gcd(a,b) = gcd(a-b,b)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-351231 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-351231 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-351231\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"393063\" commentParentId=\"351231\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ShafinKhadem\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/508696/avatar/1b5c8ae9cf51dc77.jpg'/> </a>\n <div><a href=\"/profile/ShafinKhadem\" title=\"Master ShafinKhadem\" class=\"rated-user user-orange\">ShafinKhadem</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/01/2017 09:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-393063\" href=\"?#comment-393063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-351231\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"393063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"508696\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-393063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for the nice explanation. Now the use of euclidian algorithm to solve this problem makes sense to me.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-393063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-393063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-393063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"220282\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CloverAsta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207753/avatar/45b71a38344fa830.jpg'/> </a>\n <div><a href=\"/profile/CloverAsta\" title=\"Expert CloverAsta\" class=\"rated-user user-blue\">CloverAsta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/01/2015 14:33\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-220282\" href=\"?#comment-220282\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"220282\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207753\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-220282\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain to me the solution for Problem C div2 I understand the transition from <code>k</code> to <code>k + 1</code> but the part about Euclidean algorithm is beyond me</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-220282 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-220282 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-220282\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"232136\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anajin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221428/avatar/b8f5979933e2ce3d.jpg'/> </a>\n <div><a href=\"/profile/anajin\" title=\"Expert anajin\" class=\"rated-user user-blue\">anajin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/03/2015 14:15\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-232136\" href=\"?#comment-232136\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"232136\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-232136\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>water tree can be solved by heavy-light decomposition...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-232136 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-232136 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-232136\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"454886\" commentParentId=\"232136\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cai_lw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/325977/avatar/202b61935928944.jpg'/> </a>\n <div><a href=\"/profile/cai_lw\" title=\"International Master cai_lw\" class=\"rated-user user-orange\">cai_lw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/30/2018 20:04\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-454886\" href=\"?#comment-454886\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-232136\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"454886\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"454886\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"325977\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-454886\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, this is almost the most standard problem for HLD. But their solution is cleverer and has lower time complexity. HLD is a little bit overkill for such simple operations.</p><p>Nevertheless, HLD can pass the test. My HLD solution passed in 900ms.</p><p>Also HLD was a relatively unknown algorithm to the CP community 5 years ago.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-454886 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-454886 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-454886\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"634570\" commentParentId=\"454886\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Suri429\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/776807/avatar/90399ec92a81320a.jpg'/> </a>\n <div><a href=\"/profile/Suri429\" title=\"Master Suri429\" class=\"rated-user user-orange\">Suri429</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2020 08:55\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-634570\" href=\"?#comment-634570\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-454886\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"634570\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"776807\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-634570\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain how to approach this with HLD? I am new to HLD, and not able to get any clue here. </p><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-634570 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-634570 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-634570\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"312598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/29/2016 12:31\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-312598\" href=\"?#comment-312598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"312598\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"312598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-312598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder why I did wrong in the implementation of lazy propagation for Div1D, could anyone kindly lend some help? </p><p><a href=\"//codeforces.com/contest/343/submission/20226349\">http://codeforces.com/contest/343/submission/20226349</a></p><p>Thanks in advance. =)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-312598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-312598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-312598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"357445\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/anshulgarg19\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/anshulgarg19\" title=\"Pupil anshulgarg19\" class=\"rated-user user-green\">anshulgarg19</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/02/2017 20:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-357445\" href=\"?#comment-357445\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"357445\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"244328\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-357445\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Accepted solution for the problem 343A Rational Resistance would give 6 as the output for input a = 10 and b = 7 i.e.10/7. But, if we have 5 ohm and 2 ohm resistors in parallel, then we have the same resistance value 10/7. So minimum value should be 2 resistors for this case. Kindly explain if i am wrong in understanding the problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-357445 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-357445 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-357445\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360009\" commentParentId=\"357445\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/snehil10\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/351506/avatar/522f61633a219a3b.jpg'/> </a>\n <div><a href=\"/profile/snehil10\" title=\"Expert snehil10\" class=\"rated-user user-blue\">snehil10</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/14/2017 10:08\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360009\" href=\"?#comment-360009\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-357445\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"360009\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"351506\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360009\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You have only 1-ohm resistors in the beginning. Thus it requires 5 1-ohm resistors to make a 5-ohm resistor, and 2 1-ohm resistors to make a 2-ohm resistor. So according to you answer is 7 and not 2.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360009 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360009 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360009\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"371475\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rush_123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/rush_123\" title=\"Expert rush_123\" class=\"rated-user user-blue\">rush_123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/03/2017 17:42\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-371475\" href=\"?#comment-371475\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"371475\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"439840\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-371475\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 343D — Water Tree query 1 and 2 can be solved using a dfs to find in time and out time for every node and then using segment tree But what about 3rd query how to solve it?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-371475 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-371475 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-371475\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"422269\" commentParentId=\"371475\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stringray\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/575608/avatar/2902babcf56868a2.jpg'/> </a>\n <div><a href=\"/profile/stringray\" title=\"Expert stringray\" class=\"rated-user user-blue\">stringray</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/28/2018 16:13\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-422269\" href=\"?#comment-422269\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-371475\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"422269\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"575608\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-422269\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yeah same question .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-422269 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-422269 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-422269\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"437012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ragnarok_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ragnarok_\" title=\"Newbie ragnarok_\" class=\"rated-user user-gray\">ragnarok_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2018 08:59\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-437012\" href=\"?#comment-437012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"437012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"673189\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-437012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Q.343A can anybody explain me why min resistor for 199/200 is 200.....it can be also constructed using 101 resistors(1/2+1/4+1/5+1/40+1/50)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-437012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-437012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-437012\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"573631\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SLIMSHADYNICK\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/598862/avatar/7629f1b29f0fe807.jpg'/> </a>\n <div><a href=\"/profile/SLIMSHADYNICK\" title=\"Candidate Master SLIMSHADYNICK\" class=\"rated-user user-violet\">SLIMSHADYNICK</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2020 21:03\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-573631\" href=\"?#comment-573631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"573631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"598862\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-573631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>correct!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-573631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-573631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-573631\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587715\" commentParentId=\"437012\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pied-piper\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/754580/avatar/a6fb81d49bb96665.jpg'/> </a>\n <div><a href=\"/profile/pied-piper\" title=\"Expert pied-piper\" class=\"rated-user user-blue\">pied-piper</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/11/2020 16:14\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587715\" href=\"?#comment-587715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-437012\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"587715\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"587715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"754580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It is because they are separate elements and hence they cannot be added together. Only an element and a 1 unit resistance can be added in series(or parallel)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587715\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"791297\" commentParentId=\"587715\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/15/2021 17:25\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-791297\" href=\"?#comment-791297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587715\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"791297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-791297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-791297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-791297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-791297\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"598229\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayank_ag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/644568/avatar/c1136e364e721d18.jpg'/> </a>\n <div><a href=\"/profile/mayank_ag\" title=\"Master mayank_ag\" class=\"rated-user user-orange\">mayank_ag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/05/2020 20:53\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-598229\" href=\"?#comment-598229\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"598229\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"644568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-598229\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>An alternate approach for solving D: Use of lazy segment tree over HLD & Euler path. For every filling, fill Euler path with current query number, and for emptying, fill HLD path from the root with query number. For queries, check which of the seg tree has high query number.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-598229 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-598229 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-598229\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"600816\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Asterix_11\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Asterix_11\" title=\"Pupil Asterix_11\" class=\"rated-user user-green\">Asterix_11</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/11/2020 00:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-600816\" href=\"?#comment-600816\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"600816\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1472760\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-600816\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem 344A</p> <pre><code>#include <iostream>\nusing namespace std;\nint main()\n{\n int a, i, b[100], ans;\n scanf("%d", &a);\n for(i = 0; i < a; ++i){\n scanf("%d", &b[i]);\n }\n ans = 1;\n for(i = 0; i < (a-1); ++i){\n if(b[i] != b[i + 1]){\n ++ans;}\n }\n printf("%d", ans);\n return 0;\n}\n</code></pre><p>This is my code, but I don't know how to improve it, so that the time limit won't be a problem anymore. Any help?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-600816 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-600816 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-600816\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752098\" commentParentId=\"600816\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 09:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752098\" href=\"?#comment-752098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-600816\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can make two variable for prev and current value and if they are not equal you can increment it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752098\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752075\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:25\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752075\" href=\"?#comment-752075\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752075\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752075\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Problem C, if more than one of the elements can be in parallel than for ratio 199 and 200 the answer given is 200. But we may solve this in 74. like 1/2+1/4+1/8+1/10+1/50.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752075 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752075 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752075\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752089\" commentParentId=\"752075\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sameer_Mishra100\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1387944/avatar/a32d9a31695cc097.jpg'/> </a>\n <div><a href=\"/profile/Sameer_Mishra100\" title=\"Specialist Sameer_Mishra100\" class=\"rated-user user-cyan\">Sameer_Mishra100</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 08:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752089\" href=\"?#comment-752089\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-752075\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752089\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1387944\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752089\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Okay it would be like either + denominator to the numerator or + numerator to the denominator.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752089 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752089 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752089\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"946539\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mohsina_Shaikh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1396580/avatar/6f21616a2d8d578.jpg'/> </a>\n <div><a href=\"/profile/Mohsina_Shaikh\" title=\"Newbie Mohsina_Shaikh\" class=\"rated-user user-gray\">Mohsina_Shaikh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/24/2022 06:47\">13 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-946539\" href=\"?#comment-946539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"946539\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"946539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1396580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-946539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-violet\" href=\"/profile/gen\" title=\"Candidate Master gen\">gen</a> or <a class=\"rated-user user-blue\" href=\"/profile/andreyv\" title=\"Expert andreyv\">andreyv</a> or can anyone please explain <code>Alternating Current</code> Solution.Tried so hard but not able to understand it. A</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-946539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-946539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-946539\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"959164\" commentParentId=\"946539\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rishijoshi483\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2453886/avatar/1ecf48b346fe39d0.jpg'/> </a>\n <div><a href=\"/profile/rishijoshi483\" title=\"Expert rishijoshi483\" class=\"rated-user user-blue\">rishijoshi483</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/03/2022 09:44\">12 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-959164\" href=\"?#comment-959164\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-946539\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"959164\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2453886\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-959164\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try it using stack</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-959164 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-959164 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-959164\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"966651\" commentParentId=\"959164\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Yohajji\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2854745/avatar/b31d6e4c63852741.jpg'/> </a>\n <div><a href=\"/profile/Yohajji\" title=\"Newbie Yohajji\" class=\"rated-user user-gray\">Yohajji</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2022 13:35\">11 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-966651\" href=\"?#comment-966651\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-959164\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"966651\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2854745\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-966651\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>using the stack was a brilliant aproach, thank you </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-966651 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-966651 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-966651\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1039007\" commentParentId=\"966651\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AbdelrahmanMahallawy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3189297/avatar/6b2a1658ad37caa0.jpg'/> </a>\n <div><a href=\"/profile/AbdelrahmanMahallawy\" title=\"Newbie AbdelrahmanMahallawy\" class=\"rated-user user-gray\">AbdelrahmanMahallawy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/20/2023 03:36\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1039007\" href=\"?#comment-1039007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-966651\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1039007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3189297\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1039007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>anytime </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1039007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1039007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1039007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8931\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8931 = true;\r\nvar lastPreviewContent8931 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8931] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8931] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8915\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8915, _tta: Codeforces.tta(), topicRevisionId: 44323, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:23</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128748fcb8816ab',t:'MTY5NjcwNTk0My4yOTkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1747,"cells":{"problem_id":{"kind":"string","value":"346A"},"contest":{"kind":"string","value":"346"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Alice and Bob"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Alice and Bob</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>It is so boring in the summer holiday, isn't it? So Alice and Bob have invented a new game to play. The rules are as follows. First, they get a set of <span class=\"tex-span\"><i>n</i></span> distinct integers. And then they take turns to make the following moves. During each move, either Alice or Bob (the player whose turn is the current) can choose two distinct integers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> from the set, such that the set doesn't contain their absolute difference <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span>. Then this player adds integer <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> to the set (so, the size of the set increases by one).</p><p>If the current player has no valid move, he (or she) loses the game. The question is who will finally win the game if both players play optimally. Remember that Alice always moves first.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 100</span>) — the initial number of elements in the set. The second line contains <span class=\"tex-span\"><i>n</i></span> distinct space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>) — the elements of the set.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single line with the winner's name. If Alice wins print \"<span class=\"tex-font-style-tt\">Alice</span>\", otherwise print \"<span class=\"tex-font-style-tt\">Bob</span>\" (without quotes).</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>2 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Alice<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>5 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Alice<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>5 6 7<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Bob<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first test sample. Alice moves first, and the only move she can do is to choose 2 and 3, then to add 1 to the set. Next Bob moves, there is no valid move anymore, so the winner is Alice.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"2d0461b1ffd3696bd202c3e34d4096a3\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"76ca6f0bbc2c68c0c469d82a1a1c06e9e639f443\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='2d0461b1ffd3696bd202c3e34d4096a3'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F346%2Fproblem%2FA%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='2d0461b1ffd3696bd202c3e34d4096a3'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/346\">Codeforces Round 201 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='2d0461b1ffd3696bd202c3e34d4096a3'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/346/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Games, Sprague–Grundy theorem\">\r\n games\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Number theory: Euler function, GCD, divisibility, etc\">\r\n number theory\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1600\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='2d0461b1ffd3696bd202c3e34d4096a3'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3503\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='2d0461b1ffd3696bd202c3e34d4096a3'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3503\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8896\" title=\"Codeforces Round #201\" target=\"_blank\">Codeforces Round #201</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1860:1861\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8903\" title=\"Codeforces Round #201 Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1864\" resourceName=\"Codeforces Round #201 Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/346\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/346/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/346/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/346/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/346/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/346/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/346/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/346/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_a47f4bc4b955bf4c78af13b188060d71bb686bf4\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Alice and Bob</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>It is so boring in the summer holiday, isn't it? So Alice and Bob have invented a new game to play. The rules are as follows. First, they get a set of <span class=\"tex-span\"><i>n</i></span> distinct integers. And then they take turns to make the following moves. During each move, either Alice or Bob (the player whose turn is the current) can choose two distinct integers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> from the set, such that the set doesn't contain their absolute difference <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span>. Then this player adds integer <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> to the set (so, the size of the set increases by one).</p><p>If the current player has no valid move, he (or she) loses the game. The question is who will finally win the game if both players play optimally. Remember that Alice always moves first.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 100</span>) — the initial number of elements in the set. The second line contains <span class=\"tex-span\"><i>n</i></span> distinct space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>) — the elements of the set.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single line with the winner's name. If Alice wins print "<span class=\"tex-font-style-tt\">Alice</span>", otherwise print "<span class=\"tex-font-style-tt\">Bob</span>" (without quotes).</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />2 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Alice<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />5 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Alice<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />5 6 7<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Bob<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first test sample. Alice moves first, and the only move she can do is to choose 2 and 3, then to add 1 to the set. Next Bob moves, there is no valid move anymore, so the winner is Alice.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:46</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bdc29ae976a9',t:'MTY5NjY0NjAyNi44MjYwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Games, Sprague\\u2013Grundy theorem\", \"Mathematics including integration, differential equations, etc\", \"Number theory: Euler function, GCD, divisibility, etc\"]"},"short_tags":{"kind":"string","value":"[\"games\", \"math\", \"number theory\", \"*1600\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8903"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"1c88316eb9ff5851524d80ea59ef3f32\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #201 Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #201 Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='1c88316eb9ff5851524d80ea59ef3f32'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8903\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/MinakoKojima\">MinakoKojima</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/MinakoKojima\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/MinakoKojima\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/MinakoKojima\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/MinakoKojima\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/MinakoKojima\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/MinakoKojima\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/MinakoKojima\" style=\"text-decoration:none;color:black !important;\">MinakoKojima's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8958\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8903\"> <p>Codeforces Round #201 Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a>,\r\n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><img alt=\" \" src=\"/predownloaded/41/3f/413f7303374a112dddc1e63e29cfc12924514cd7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><h1>Overview</h1><p>In DIV 1, there are 4 interesting problems together with a normal one. We think it is reasonable because we can't have a round fullly with intelligence. Problem A, C have weak pretests while others intended to be strong. About more then 200 participants solve A in the early 45mins, then a few of them start from C while most of the other start from B. </p><p>Problem B is a rather standard problem, but if you're unfamiliar with the algorithm, it can be very hard. Problem C is a more intersting problem. As the name implies, there was <a href=\"//codeforces.com/problemset/problem/251/C\">a similar version</a> in the previous round before, but this time it has a brand new constrains.(So here we have a psychology experiment: could different constrains make people thinking in a slightly different way?ww)</p><p>The standard solution of problem C is <span class=\"tex-span\"><i>O</i>((<i>b</i> - <i>a</i>) + <i>nlogn</i>)</span>. The first expected correct solution was written by <a class=\"rated-user user-orange\" href=\"/profile/zeliboba\" title=\"International Master zeliboba\">zeliboba</a>. <a href=\"//codeforces.com/contest/346/submission/4512654\">http://codeforces.com/contest/346/submission/4512654</a></p><p>After that, some people start to solve problem D. Problem D looks like a hard dp problem on a graph at the first glance, the key point is how to avoid the circle in the transfer equation. It turn out to be elegant after you could found a right order of the evaluation. Problem E is challenging which you need find a way to transform the original question into a smaller scale, and cut off many many corner cases ... And in the very end, you find a way like binary search to get <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span> as the time complexity. No one manage to solve problem E during the contest, maybe <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> is the man who closest to it.</p><p>The winner comes to <a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"Grandmaster cgy4ever\">cgy4ever</a>, because he found the draw-black in his previous C submission during the very beginning even when there is nobody hack him! He resubmit it decisively and get back when finished problem D. After that, he use the same trick which made him failed before to hack others and got a handsomely rewards. The second place went to <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a>, because of the combination of decent speed in A, B, C, D.</p><p>Problem B belongs to me, problem C belongs to <a class=\"rated-user user-violet\" href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\">CMHJT</a> and others belong to <a class=\"rated-user user-orange\" href=\"/profile/UESTC_Nocturne\" title=\"International Master UESTC_Nocturne\">UESTC_Nocturne</a>. The illustrator of problem C is <a href=\"http://www.pixiv.net/member_illust.php?mode=medium&illust_id=38602657\">Chairman Miao(貓主席)</a>.</p><h1>Editorial</h1><h3><a href=\"//codeforces.com/problemset/problem/346/A\">Problem A. Alice and Bob</a></h3><h4>Brief description:</h4><p>Alice and Bob play a game, the rules are as follows: First, they will get a set of <span class=\"tex-span\"><i>n</i></span> distinct numbers. And then they take turns to do the following operations. During each operation, either Alice or Bob can choose two different numbers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> from the set, as long as <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> is not in the set, then they add it to the set. The person who can not choose two numbers successfully will lose the game. The question is who will finally win the game if both of them do operations optimally. Remember that Alice always goes first.</p><h4>Analysis:</h4><p>First, no matter what happend, the number set we get at the very endding will be same all the time. Let's say <span class=\"tex-span\"><i>d</i> = <i>gcd</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}. Then the set in the endding will be some things like {<span class=\"tex-span\"><i>d</i></span>, <span class=\"tex-span\">2<i>d</i></span>, <span class=\"tex-span\">3<i>d</i></span>, ... <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}}. So there is always <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub>} / <i>d</i></span> — <span class=\"tex-span\"><i>n</i></span> rounds. And what we should do rest is to check the parity of this value.</p><h3><a href=\"//codeforces.com/problemset/problem/346/B\">Problem B. Lucky Common Subsequence</a></h3><h4>Brief description:</h4><p>You have been given two strings <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and <span class=\"tex-span\"><i>virus</i></span>, and you have to find the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> without <span class=\"tex-span\"><i>virus</i></span> as a substring.</p><h4>Analysis:</h4><p>This is a rather classical problem, let's say if there is no virus, then it is the classical **LCS ** problem. You can solve this by a <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> dynamic programing.</p><p>When consider about the virus, we should add 1 more dimension on the state to trace the growth of the virus. It can be done by wheather <strong>Aho-Corasick automation</strong>, or <strong>KMP</strong> when there is only one virus in this case. The overall time complexity is <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">3</sup>)</span>.</p><h3><a href=\"//codeforces.com/problemset/problem/346/C\">Problem C. Number Transformation II</a></h3><h4>Brief description:</h4><p>You have a number <span class=\"tex-span\"><i>b</i></span>, and want to minus it to <span class=\"tex-span\"><i>a</i></span>, what you can do in each step is weather subtract 1 or <span class=\"tex-span\"><i>b</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> from <span class=\"tex-span\"><i>b</i></span>. And we ask what is the minimum number of steps you need.</p><h4>Analysis:</h4><p>I bet there is a few people know the greedy method even if he/she have solved the early version before.</p><p><a href=\"//codeforces.com/problemset/problem/251/C\">Codeforces #153 Div 1. Problem C. Number Transformation</a></p><p>Let dp[k] denotes the minimum number of steps to transform b+k to b. In each step, you could only choose i which makes b+k-(b+k) mod x[i] minimal to calc dp[k]. It works bacause dp[0..k-1] is a monotone increasing function. Proof: - Say dp[k]=dp[k-t]+1.If t==1, then dp[0..k] is monotone increasing obviously.Otherwise dp[k-1]<=dp[k-t]+1=dp[k] (there must exist a x[i] makes b+k-1 also transform to b+k-t,and it is not necessarily the optimal decision of dp[k-1]). So dp[k] is a monotone increasing function, we can greedily calc dp[a-b].</p><p>In the first glance, it looks like something which will run in square complexity. But actually is linear. That is because, we could cut exactly max{<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>} in each 2 step. It can be proof by induction.</p><p>So the remians work is to delete those same <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>, and watch out some situation could cause degeneration. Many of us failed in this last step and got <strong>TLE</strong></p><h3><a href=\"//codeforces.com/problemset/problem/346/D\">Problem D. Robot Control</a></h3><p>Let's dp from t to s.</p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>Here dp[u] means, the minimum number of orders mzry1992 needs to send in the worst case. The left-hand-side is sending order while the right-hand side is not. At the beginning, we have dp[t] = 1, and dp[s] will be the answer.</p><p>We can see there is circular dependence in this equation, in this situation, one standard method is using Bellman-Ford algorithm to evaluate the dp function.</p><p>But it is not appropriate for this problem.</p><p>(In fact, we add a part of targeted datas in pretest, these datas are enough to block most of our <a href=\"https://en.wikipedia.org/wiki/Bellman%E2%80%93Ford_algorithm\">Bellman-Ford algorithm</a>, although there is still a few participator can get accepted by Bellman-Ford algorithm during the contest.</p><p>Check <a class=\"rated-user user-violet\" href=\"/profile/rares.buhai\" title=\"Candidate Master rares.buhai\">rares.buhai</a>'s <a href=\"//codeforces.com/contest/346/submission/4520171\">solution</a></p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>The expected solution is evaluating the dp function as the increased value of dp[u] itself. Further analysis shows, wheather we decided sending order or not in u can be judged as the out-degree of u.</p> <pre><code><br />while (!Q.empty()) {\n u = Q.front(), Q.pop_front()\n for each edge from v to u\n --out_degree[v]\n\tif (out_degree[v] == 0) {\n relax dp[v] by dp[u]\n if success, add v to the front of Q\n\t}\n\telse{\n\t relax dp[v] by dp[u] + 1\n\t if success, add v to the back of Q\n }\t\n }\n</code></pre><p>Check <a class=\"rated-user user-orange\" href=\"/profile/Ra16bit\" title=\"International Master Ra16bit\">Ra16bit</a>'s <a href=\"//codeforces.com/contest/346/submission/4519668\">solution</a> to see how it works.</p><h3><a href=\"//codeforces.com/problemset/problem/346/E\">Problem E. Doodle Jump</a></h3><h4>Brief description:</h4><p>You have been give <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>, <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>h</i></span> (gcd(<span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>) = 1), For each <span class=\"tex-span\"><i>ai</i></span> mod <span class=\"tex-span\"><i>p</i></span>, (<span class=\"tex-span\"><i>i</i></span>∈[1, n]), check weather the maximum distance in neighborhood after sorting is <= <span class=\"tex-span\"><i>h</i></span>. </p><h4>Analysis:</h4><p>Take <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 for example ... Divided the numbers in group.</p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 18\n</code></pre><p>We start a new group when the number > P</p><p>We found the difference between the elements of the first group is 5, The subsequent is filling some gap between the them ...</p><p>After some observation we could found that we should only consider into one gap ...(e.g. [0, 5] or [15, 20] or [20, 25] ... ) </p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>That says .. <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 is roughly equal to some things in small scale?</p><p>So let's check it in detail. Lemma 1. In any case, the gap after 20 won't better than any gap before it.</p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>For example, in this case, the gap after 20 is: 20, 22 And it has 16 in [15, 17] but no 21. </p><p>Is there any chance that [20, 23] is better than [15, 20]?</p><p>No, that is because, when there is no 21, then (19+5)%23 = 1, go to next floor. and there is no corresponding gap after 20 ([22, 24]) for this gap ([17, 19])</p><p>So we only need to consider [15, 20] ... and we found [15, 20] is roughly equal to [0, 5]</p> <pre><code>e.g. : 15 20 17 19 16 18 \nequal: 0 5 2 4 1 3\n</code></pre><p>we say 'roughly' because we havn't check some boundary case like there is 3 but on 18 ... </p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 \n</code></pre><p>If it happend, we should remove the number 3. .. If we can remove the element 5, then we can from a=5, p=23 to a'=2, p'=5 ...(n' = an/p, a' = a-p%a, if there is 3 but no 18, n'=n'-1)</p><p>The rest things is to discuss wheather 5 is necessary or not.</p><p>Let's we have:</p> <pre><code>0 2 4\n1 3\n</code></pre><p>If the 2*n'<5, then there is only one floor, the answer is max(2, 5-2*n'). If there is more than one floor, we could conclude that 5 is useless.</p><p>Proof: Elemets in 1st floor is: </p> <pre><code>0 a 2a 3a ...\n</code></pre><p>Let's say the maximum elements in 1st floor is x, then the minimum element in the 2nd floor is b0 = x+a-p, because b0 — a = x-p, so the difference between b0 and a is equal to the difference between x and p. That is, we can consider [b0, a] rather than [x, p], when there is a element insert in [b0, a], there must be some element insert in [x, p] in the same position.</p><p>So we have have succeeded to transform our original problem into a small one. Of couse, this problem havn't been solved, we haven't consider the time complexity. Says a' = a — p%a, when p = a+1, then a' = a-1, but we have <span class=\"tex-span\"><i>a</i></span> equal to 10^9, it won't work.</p><p>But, let's we have A1, A2, ... An ... and we subtract <span class=\"tex-span\"><i>d</i></span> from all of them, the answer won't be changed. So we can use p%a substitute for a-p%a, this is equivalent to we subtract %p% from all of them ...</p><p>So we set a' = min(a-p%a, p%a), so a'<=a/2, therefore, the final time complexity is <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span>.</p><p>You can check <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> <a href=\"//codeforces.com/contest/346/submission/4523388\">'s solution</a> for detail.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/346\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/347\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-4906-8958\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"4906\",\n blogEntryId: \"8903\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+56</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/MinakoKojima\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/MinakoKojima\">\n MinakoKojima\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8903#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8903#comments\">\n 66\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8974\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (56)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146290\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mohammadrdeh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/47/avatar/91eee3f7a5ec41f6.jpg'/> </a>\n <div><a href=\"/profile/mohammadrdeh\" title=\"Specialist mohammadrdeh\" class=\"rated-user user-cyan\">mohammadrdeh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146290\" href=\"?#comment-146290\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146290\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"14\"\r\n data-commentUserId=\"47\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+14</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146290\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>there is a typo: "... the classical <strong>LCA</strong> problem ..." => <strong>LCS</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146290 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146290 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146290\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146291\" commentParentId=\"146290\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146291\" href=\"?#comment-146291\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146290\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146291\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146291\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you. Fixed. m(_ _)m</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146291 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146291 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146291\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146297\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 05:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146297\" href=\"?#comment-146297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Actually our standard solution to C is O(b-a+n). O(b-a+n),O(b-a+nlogn),O((b-a+n)logn) are all able to pass during the test.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146297\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146335\" commentParentId=\"146297\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mmaxio\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/486/avatar/4bb53c24fc9e4c1.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/mmaxio\" title=\"International Master mmaxio\" class=\"rated-user user-orange\">mmaxio</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 17:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146335\" href=\"?#comment-146335\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146297\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146335\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146335\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"486\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146335\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>oh, never mind</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146335 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146335 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146335\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146299\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shashwat.gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6204/avatar/67f8e17c53f70578.jpg'/> </a>\n <div><a href=\"/profile/shashwat.gupta\" title=\"Specialist shashwat.gupta\" class=\"rated-user user-cyan\">shashwat.gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146299\" href=\"?#comment-146299\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146299\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"6204\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146299\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Problem B: Can you Explain little bit more on How "Aho-Corasick automation, or KMP" can help in figuring out smallest string that does not contain virus.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146299 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146299 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146299\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146300\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146300\" href=\"?#comment-146300\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146300\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146300\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For B, I already had the intuitive idea that this problem will be solved by either Aho-Corasick algorithm or KMP with dp, but I could not formalize the idea of states transition in dp. Could you please just provide the state in your dp algorithm?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146300 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146300 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146300\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146354\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146354\" href=\"?#comment-146354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146354\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Original problem can be solved by dp with two parameters DP[Len(s)] [Len(t)]. <a href=\"https://en.wikipedia.org/wiki/Longest_common_subsequence_problem\">http://en.wikipedia.org/wiki/Longest_common_subsequence_problem</a></p><p>To solve B you need to modificate it to DP[Len(s)][Len(t)][Len(virus)-1] where third parameter means maximum length of suffix of LCS that equal to prefix of virus.</p><p>To easy check where we go from K state (third parameter) by character C we can make automat on prefix function by virus.</p><p>Then if we stand in DP[i][j][k] :<br /> 1) if(s[i] == t[j] and Automat[k][c]<Len(virus) we try to relax DP[i+1][j+1][Automat[k][c]]<br /> 2) Try to relax DP[i][j+1][k] and DP[i+1][j][k]</p><p><strong>UPD</strong> My solution: <a href=\"//codeforces.com/contest/346/submission/4532899\">http://codeforces.com/contest/346/submission/4532899</a> (hope it understandable)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146354\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146357\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146357\" href=\"?#comment-146357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>got it, many thanks to you man :) Also understood why KMP tag mentioned in the problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146357\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146493\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lama\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/72190/avatar/735906a91d1576e3.jpg'/> </a>\n <div><a href=\"/profile/lama\" title=\"Expert lama\" class=\"rated-user user-blue\">lama</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 18:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146493\" href=\"?#comment-146493\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146493\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146493\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) Can you please explain what "maximum length of suffix of LCS that equal to prefix of virus" means? 2) What is an automat?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146493 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146493 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146493\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146519\" commentParentId=\"146493\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/25/2013 05:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146519\" href=\"?#comment-146519\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146493\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146519\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146519\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146519\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) We stand in DP[i][j][k]-state (in which we store longest LCS), virus = "virus" <br /> Let's go from k = 0 to 4,then:</p> <pre><code>0) DP[i][j][0] means that finded LCS not ends on "v" or "vi" or "vir" or "viru" or "virus". (example: "a")\n\n1) DP[i][j][1] means that finded LCS ends on "v", but not on "vi" or "vir" or "viru" or "virus". (example: "av")\n\n2) DP[i][j][2] means that finded LCS ends on "vi", but not on "vir" or "viru" or "virus". (example: "avi")\t\n\n3) DP[i][j][3] means that finded LCS ends on "vir", but not on "viru" or "virus". (example: "avir")\n\n4) DP[i][j][4] means that finded LCS ends on "viru", but not on "virus". (example: "aviru")\n\nWe take "longest suffix of LCS that equal prefix of virus", because virus could be: "vvvvv" or "ababv" (and infinite others)\n If LCS = "avvv" - it ends on "v","vv","vvv". (virus = "vvvvv")\n If LCS = "aabab" - it ends on "ab" and "abab". (virus = "ababv")\n</code></pre><p><a href=\"https://en.wikipedia.org/wiki/Knuth%E2%80%93Morris%E2%80%93Pratt_algorithm\">KMP</a></p><p>2) <a href=\"https://en.wikipedia.org/wiki/Automata_theory\">http://en.wikipedia.org/wiki/Automata_theory</a></p><p>Can't find nothing about automaton on prefix-function in english. I hope you will be able understand <a href=\"http://e-maxx.ru/algo/prefix_function\">this</a> with some translator (google translate for example).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146519 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146519 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146519\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"551712\" commentParentId=\"146519\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/srv_twry\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/447741/avatar/d1a80b00eb029c2b.jpg'/> </a>\n <div><a href=\"/profile/srv_twry\" title=\"Expert srv_twry\" class=\"rated-user user-blue\">srv_twry</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/19/2019 12:58\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-551712\" href=\"?#comment-551712\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146519\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"551712\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"447741\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-551712\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Fortunately, the e-maxx article on Prefix function has been translated in English and can be found here: <a href=\"https://cp-algorithms.com/string/prefix-function.html#toc-tgt-12\">prefix-function: automaton on prefix-function</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-551712 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-551712 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-551712\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"768401\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ttbbnnn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1694563/avatar/ff85df0301cf6f76.jpg'/> </a>\n <div><a href=\"/profile/ttbbnnn\" title=\"Master ttbbnnn\" class=\"rated-user user-orange\">ttbbnnn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2021 20:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-768401\" href=\"?#comment-768401\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"768401\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1694563\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-768401\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My solution for B got a WA on test 41 and I don't know why :<, please help me with this code: <a href=\"https://codeforces.com/contest/346/submission/109283664\">https://codeforces.com/contest/346/submission/109283664</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-768401 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-768401 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-768401\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146301\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146301\" href=\"?#comment-146301\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146301\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146301\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146301\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"So the remians work is to delete those same xi, and watch out some situation could cause degeneration. Many of us failed in this last step and got TLE", I really could not understand this. What you you mean by degeneration in this case? Please explain this last important step.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146301 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146301 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146301\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146302\" commentParentId=\"146301\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:37\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146302\" href=\"?#comment-146302\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146301\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146302\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146302\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>suppose b=1, all x[i]>a, what will happen?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146302 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146302 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146302\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146304\" commentParentId=\"146302\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146304\" href=\"?#comment-146304\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146302\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146304\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146304\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As b = 1, All x[i] > a. Then a % x[i] = a. So if we take this, then we will lead to a — a = 0, which is less than b. So we need to move one by one, so answer would be a.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146304 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146304 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146304\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146309\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146309\" href=\"?#comment-146309\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146309\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146309\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Alice and Bob problem how do you prove that you will always get {d, 2d, 3d, ... max{xi}} in the end. It is easy to see but I am unable to prove it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146309 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146309 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146309\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146365\" commentParentId=\"146309\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marat.snowbear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98082/avatar/1499cf6d0c86172.jpg'/> </a>\n <div><a href=\"/profile/marat.snowbear\" title=\"International Master marat.snowbear\" class=\"rated-user user-orange\">marat.snowbear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146365\" href=\"?#comment-146365\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146309\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146365\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"98082\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146365\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I convinced myself like this:</p> <ol> <li>Prove that we will be able to get d by some sequence of subtractions.</li> <li>Prove that we will be able to generate {d, 2d, 3d, ...}</li> <li>Prove that we will not be able to get anything else except for { d, 2d, 3d, ... }</li> </ol><p>In details:</p> <ol> <li><p>See <a href=\"https://en.wikipedia.org/wiki/Euclidean_algorithm\">Euclidean algorithm for finding GCD</a>. If you will look into the description or code you will see that it does exactly what is asked in this problem — subtracts numbers one from another. And the result is GCD of original two numbers. So you can see that by some sequence of subtractions you can get GCD.</p></li> <li><p>If you already have d which GCD of all the numbers then you can easily fill all the gaps in { d, 2d, 3d, ..., max } sequence by starting subtracting d from { max, max — d, max — 2d, ... }. So you will get the intended set.</p></li> <li><p>You cannot subtract two numbers a and b which have GCD(a, b) = d and get result which won't be dividable by d. So if you start with set where every numbers can be divided by d then no matter what you subtract you will always have the result which is also dividable by d.</p></li> </ol></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146365 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146365 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146365\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146390\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 16:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146390\" href=\"?#comment-146390\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146390\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146390\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, got it. Thanks!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146390 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146390 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146390\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"774539\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/25/2021 20:24\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-774539\" href=\"?#comment-774539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"774539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-774539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-774539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-774539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-774539\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146310\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i_coder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i_coder\" title=\"Expert i_coder\" class=\"rated-user user-blue\">i_coder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146310\" href=\"?#comment-146310\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146310\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"41979\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146310\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Is this the final editorial (except the D problem) ? The explanations to problems B and C are very limited and not at all well elaborated.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146310 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146310 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146310\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146314\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146314\" href=\"?#comment-146314\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146314\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146314\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can you tell me that why the number of rounds in Problem A will be max(xi)/d-n ? How do you come to this point ? can you please tell me this as am not to figure out this thing ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146314 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146314 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146314\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146316\" commentParentId=\"146314\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:45\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146316\" href=\"?#comment-146316\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146314\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146316\" revisionCount=\"7\" revision=\"7\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">7</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146316\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146316\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>take example <br /> 3 9 54 <br /> gcd (3, 9, 54) = 3 <br /> Now total rounds possible including (3, 9, 54) =<br />all multiples of 3 upto 54 <br /> 3, 6, 9, 12, 15, 18 ... 54 <br /> </p><p>So total count of these numbers = 54 / 3 = 18. <br /> </p><p>Now as out of these numbers 3 numbers are already taken, so subtract 3 <br /> so rounds remaining = 18 — 3 = 15 </p><p>Now it is very easy to generalize for 3 being d and 54 being n</p><p>answer would be n / d — n. <br /> I hope it is clear now :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146316 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146316 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146316\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146319\" commentParentId=\"146316\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146319\" href=\"?#comment-146319\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146316\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146319\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146319\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes, it is more clear to me now. but one thing is that how did you approach to gcd thing ? I understood the problem, the logic and all. how did you approach that it will be done using gcd thing and all ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146319 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146319 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146319\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146322\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146322\" href=\"?#comment-146322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146322\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My Ideas during solving the problem: <br /> all the examples had gcd 1. So I directly thought answer as max(xi) — n. <br /> But I thought it can not be too simple, I need to think more. <br /> So I took a case 2 4 6, I immediately found I am wrong in this case. <br /> Then the idea came into mind that if gcd of numbers is g. then we can not create any number not divisible by g because (g *k1 — k * k2) = g * (k1 — k2). </p><p>So Finally I coded it and got accpeted :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146322\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146338\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 19:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146338\" href=\"?#comment-146338\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146338\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146338\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>given the numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>, what is the minimum positive value you can achieve by combining them? </p><p>Let's write down the equation: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>·<i>x</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub>·<i>x</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>n</i></sub>·<i>x</i><sub class=\"lower-index\"><i>n</i></sub> = <i>d</i></span>, where <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> are some unknown integers. </p><p>It is, as you can see, none other than linear Diophantine equation. And it is known there is no solutions if <span class=\"tex-span\"><i>d</i></span> is not a multiple of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span> </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146338 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146338 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146338\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146317\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/subway\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123924/avatar/706e86f587cbabf0.jpg'/> </a>\n <div><a href=\"/profile/subway\" title=\"Expert subway\" class=\"rated-user user-blue\">subway</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146317\" href=\"?#comment-146317\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146317\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146317\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@hellodear-the final set will contain all elements {d,2d,3d,..max(Xi)} (d=gcd of all elements) so total no. of elements in final set =max(Xi)/d since initially we have 'n' elements total no. of new elements to be added in set to make it complete=(max(Xi)/d)-n.. hope this helps you..:)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146317 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146317 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146317\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146320\" commentParentId=\"146317\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146320\" href=\"?#comment-146320\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146317\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146320\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146320\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in this thing, I was applying some game theory, but it doesn't include anything like that. when the question says optimally, then how do you form examples so as to test your code on them ? because optimally means in the best they can. can you elaborate ? thanks to you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146320 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146320 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146320\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146324\" commentParentId=\"146320\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146324\" href=\"?#comment-146324\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146320\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146324\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146324\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146324\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>optimality argument is simple and also given in the editorial itself. <br /> As total you numbers finally would be {d, 2 * d,, .,, max (xi)}. <br /> Hence whatever you add to the these set, no other person will be able to add that as he has to add a new number everytime to this test. <br /> So outcome depend on the parity of turns.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146324 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146324 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146324\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146325\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sinamosavi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/87557/avatar/bde58fa97bcc5eb0.jpg'/> </a>\n <div><a href=\"/profile/sinamosavi\" title=\"Pupil sinamosavi\" class=\"rated-user user-green\">sinamosavi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146325\" href=\"?#comment-146325\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146325\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"87557\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146325\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the complete proof for A.Div1 is not that much straightforward. Maybe I'm making it too much difficult, but this is my complete proof:</p><p>First by induction, we prove that the numbers in the end will be <span class=\"tex-span\"><i>a</i>, 2<i>a</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Let <span class=\"tex-span\"><i>g</i> = <i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ... , <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span>. It's trivial that in the end <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>. Assume that <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>, because our numbers will be <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), 2<i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>, so we would have a new gcd. That's a contradiction, so <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) = <i>g</i></span> and our numbers will be <span class=\"tex-span\"><i>g</i>, 2<i>g</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Each move adds one number and in the end there will be <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e6ac12549498d8aaad3d63270d12497bc74a9f84.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> numbers, so the answer wil be the parity of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/48ba1bfd0fa315ab1595947b8e046b4cc211b908.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Sorry for my bad English.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146325 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146325 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146325\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146332\" commentParentId=\"146325\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146332\" href=\"?#comment-146332\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146325\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146332\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-13\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146332\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What about this test <code>2 3 5</code>? <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≠ <i>gcd</i></span></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146332 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146332 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146332\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146333\" commentParentId=\"146332\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146333\" href=\"?#comment-146333\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146332\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146333\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146333\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Oops. You've meant that <span class=\"tex-span\"><i>a</i></span> — is the result. Sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146333 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146333 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146333\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146334\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 16:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146334\" href=\"?#comment-146334\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146334\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146334\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146334\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>But how to prove that there is always a way to choose <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> while the number of the current round less than the maximum number of rounds? (Div2C)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146334 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146334 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146334\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146339\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:22\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146339\" href=\"?#comment-146339\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146339\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146339\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146339\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If gcd{xi}＝1, then for every xi there must exist ti to make sum｛xi*ti｝＝1. </p><p>(For example, x1＝5,x2＝7,then t1＝3,t2＝-2.x1*t1＋x2*t2＝1.)</p><p>And sum{xi*ti} can be performed in a few turns. ( (5-(7-5))-(7-5). )</p><p>And if we can get 1, then what number between [1,max{xi}] can't we get？</p><p>if gcd{xi}≠1.the proof is similar.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146339 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146339 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146339\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146341\" commentParentId=\"146339\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146341\" href=\"?#comment-146341\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146339\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146341\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146341\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why there is must exist such t[i]?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146341 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146341 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146341\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146366\" commentParentId=\"146341\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146366\" href=\"?#comment-146366\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146341\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146366\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146366\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You must know if gcd(a,b)＝1, there must exist x and y to make ax＋by＝1. It can be proved from this.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146366 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146366 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146366\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146376\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146376\" href=\"?#comment-146376\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146376\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146376\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146376\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So.. If we divide all the numbers by GCD, and after that a pair of coprime numbers have appeared, we always can reach 1. Let's choose coprime <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, then <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> will be also coprime with <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, and it will be less then <span class=\"tex-span\"><i>max</i>(<i>x</i>, <i>y</i>)</span>. So we can choose <span class=\"tex-span\"><i>mid</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>x</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>min</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>y</i><sub class=\"lower-index\">1</sub></span>, and they are coprime, and <span class=\"tex-span\">|<i>x</i><sub class=\"lower-index\">1</sub> - <i>y</i><sub class=\"lower-index\">1</sub>|</span> will be less than <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>. And etc. by induction. But what to do if there is not a pair of coprime numbers after dividing by GCD? For example <code>35 45 63</code>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146376 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146376 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146376\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146404\" commentParentId=\"146376\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146404\" href=\"?#comment-146404\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146376\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146404\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146404\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146404\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>63*2＋45*5＋35*(-10)＝1</p><p>Because gcd (35,45)＝5, we can consider 35 and 45 as one number 5x. Because gcd(5,63)＝1, so there must exist x,y to make 5x＋63y＝1.</p><p>So here comes a tragedy. We can get 5 first. Then we use this number together with 63 to make 1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146404 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146404 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146404\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146346\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KiAsaGibona\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/KiAsaGibona\" title=\"Specialist KiAsaGibona\" class=\"rated-user user-cyan\">KiAsaGibona</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 21:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146346\" href=\"?#comment-146346\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146346\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146346\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"99053\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146346\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Someone please explain the greedy idea of (Div 1 C) (Number Transformation II). Thanks in advance :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146346 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146346 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146346\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146367\" commentParentId=\"146346\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 09:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146367\" href=\"?#comment-146367\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146346\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146367\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146367\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's a pretty simple greedy idea: Just pick the <code>x</code> that makes the value of <code>a</code> smallest after applying the operation <code>a = a - a%x</code> (or subtract 1 if no choice for <code>x</code> makes <code>a</code> smaller). The proof why this works is given in the editorial: it is never better to get a larger number, so you should get the smallest one you can.</p><p>As listed on the last paragraph of the editorial you have to be careful to remove all <code>x</code> that are either duplicates or cannot be used anymore (<code>a - (a%x)</code> is smaller than <code>b</code>), otherwise you will get TLE.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146367 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146367 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146367\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146382\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146382\" href=\"?#comment-146382\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146382\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146382\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146382\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>how to find this x for each number?</p><p>we will iterate on all x[i]s and only delete x[i]s when x[i] > a?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146382 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146382 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146382\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146405\" commentParentId=\"146382\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146405\" href=\"?#comment-146405\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146382\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146405\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146405\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Iterate through all x[i]s and delete them when a — (a%x[i]) is smaller than b (if you only delete when x[i] > a, you will also get TLE).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146405 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146405 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146405\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146625\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 17:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146625\" href=\"?#comment-146625\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146625\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146625\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm really striving to understand why the algorithm turns out to be linear instead of quadratic... I know the editorial says "That is because, we could cut exactly <span class=\"tex-span\"><i>max</i>{<i>xi</i>}</span> in each 2 step.", but I can't really get what it means :\\</p><p>Can you give me a hint? Thanks :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146625 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146625 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146625\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146643\" commentParentId=\"146625\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/xenoslash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88090/avatar/f75f8cbc20d6133f.jpg'/> </a>\n <div><a href=\"/profile/xenoslash\" title=\"Expert xenoslash\" class=\"rated-user user-blue\">xenoslash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 19:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146643\" href=\"?#comment-146643\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146625\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146643\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146643\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"88090\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146643\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have an easy intuition of cutting at least max{xi} in O(1) steps, not sure what was the intended 2 step proofs though. I am going to use xi to refer to max{xi}, and assume that proper care is taken to only keep the relevant xi's.</p><p>When we do a-(a % xi), we bring caused a to be the next largest integer <= a that is a multiple of xi, since now new_a % xi = 0. Then, if a is divisible by xi, you can do.., do a-1 (causing it to be non-divisible by xi), then finally a-(a%xi) again. In this 3 step sequence you have brought a down to the next lower multiple of xi, and have essentially cut max{xi} in O(1) number of steps.</p><p>Sample code : <a href=\"//codeforces.com/contest/346/submission/4545367\">http://codeforces.com/contest/346/submission/4545367</a> Yeah I used tree set so it's not exactly O(n).. but hash set keeps giving me TLE :(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146643 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146643 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146643\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146689\" commentParentId=\"146643\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2013 12:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146689\" href=\"?#comment-146689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146643\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you very much, that was really eye-opening! This is why I love Codeforces, great community! :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146689\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146371\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Corvo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/11909/avatar/8404ac1aff5270ec.jpg'/> </a>\n <div><a href=\"/profile/Corvo\" title=\"Pupil Corvo\" class=\"rated-user user-green\">Corvo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 12:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146371\" href=\"?#comment-146371\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146371\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"11909\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146371\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please explain why the problem is solved through the GDC (A)? I tried like <a href=\"https://codeforces.com/contest/347/submission/4535232\">this</a>, but I still can not understand why you can not do. Please give a short test on which the decision falls. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146371 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146371 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146371\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146375\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146375\" href=\"?#comment-146375\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146375\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146375\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><pre><code>3\n14 4 2\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146375 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146375 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146375\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146378\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akashdeep\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/39866/avatar/6f66d1bbe26ef4ca.jpg'/> </a>\n <div><a href=\"/profile/akashdeep\" title=\"International Master akashdeep\" class=\"rated-user user-orange\">akashdeep</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146378\" href=\"?#comment-146378\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146378\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"39866\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146378\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Because only those numbers are possible in the game which are multiple of gcd. See this simplest test case</p> <pre><code>2\n4 6\n</code></pre><p>The only number possible in the game is (6-4) i.e. 2, but in your code u are assuming that somehow these (1,2,3,5) numbers can be obtained which is a wrong assumption.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146378 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146378 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146378\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146408\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/NegaTeeF\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/NegaTeeF\" title=\"Master NegaTeeF\" class=\"rated-user user-orange\">NegaTeeF</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 20:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146408\" href=\"?#comment-146408\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146408\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"65829\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146408\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Explain please, how to do Div1-D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146408 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146408 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146408\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146410\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/irakli_p\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29034/avatar/d879a3156498c6c7.jpg'/> </a>\n <div><a href=\"/profile/irakli_p\" title=\"Expert irakli_p\" class=\"rated-user user-blue\">irakli_p</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 21:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146410\" href=\"?#comment-146410\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146410\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29034\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146410\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i didn't understand Div 2 — D can someone explain it to me please </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146410 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146410 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146410\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146443\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/suiyuan2009\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49923/avatar/9065a92c0b30b883.jpg'/> </a>\n <div><a href=\"/profile/suiyuan2009\" title=\"Master suiyuan2009\" class=\"rated-user user-orange\">suiyuan2009</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 13:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146443\" href=\"?#comment-146443\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146443\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49923\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146443\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>problem B,ac automachine is doing the thing that belong to kmp</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146443 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146443 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146443\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146452\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 17:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146452\" href=\"?#comment-146452\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146452\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146452\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div1_E: Should the "Doodler" jump over the platform which H = P ? I just confused about that.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146452 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146452 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146452\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146480\" commentParentId=\"146452\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 11:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146480\" href=\"?#comment-146480\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146452\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146480\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146480\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OK I got the answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146480 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146480 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146480\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146463\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146463\" href=\"?#comment-146463\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146463\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"44\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+44</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146463\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>still waiting for D tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146463 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146463 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146463\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147566\" commentParentId=\"146463\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/05/2013 05:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147566\" href=\"?#comment-147566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146463\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>.. Update .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147566\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"235917\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/saurabhverma\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/143428/avatar/48808a8d5db775d4.jpg'/> </a>\n <div><a href=\"/profile/saurabhverma\" title=\"Expert saurabhverma\" class=\"rated-user user-blue\">saurabhverma</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2015 20:05\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-235917\" href=\"?#comment-235917\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"235917\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"143428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-235917\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In my approach to problem div1 B, I calculated longest common subsequence, prepended virus to it, calculated the Z function and deleted every character which had z[i] >= virus.size(). I don't think my approach is wrong. Can someone tell me if my code is wrong or the approach has some flaw. Thanks. Submission : <a href=\"//codeforces.com/contest/346/submission/11491420\">http://codeforces.com/contest/346/submission/11491420</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-235917 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-235917 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-235917\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"530287\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arpit4427\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/717924/avatar/90dcbc94a1e57cf.jpg'/> </a>\n <div><a href=\"/profile/arpit4427\" title=\"Expert arpit4427\" class=\"rated-user user-blue\">arpit4427</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/26/2019 14:04\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-530287\" href=\"?#comment-530287\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"530287\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"530287\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"717924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-530287\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone explain how to solve this problem <a href=\"/contest/346/problem/B\" title=\"Codeforces Round 201 (Div. 1)\">346B - Lucky Common Subsequence</a>? I have went thorugh the editorial but I could not understand.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-530287 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-530287 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-530287\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8974\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8974 = true;\r\nvar lastPreviewContent8974 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8974] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8974] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:24</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812874998e81759f',t:'MTY5NjcwNTk0NS4wMjkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1748,"cells":{"problem_id":{"kind":"string","value":"346B"},"contest":{"kind":"string","value":"346"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Lucky Common Subsequence"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Lucky Common Subsequence</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>3 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>512 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>In mathematics, a <span class=\"tex-font-style-it\">subsequence</span> is a sequence that can be derived from another sequence by deleting some elements without changing the order of the remaining elements. For example, the sequence <span class=\"tex-font-style-tt\">BDF</span> is a subsequence of <span class=\"tex-font-style-tt\">ABCDEF</span>. A <span class=\"tex-font-style-it\">substring</span> of a string is a continuous subsequence of the string. For example, <span class=\"tex-font-style-tt\">BCD</span> is a substring of <span class=\"tex-font-style-tt\">ABCDEF</span>.</p><p>You are given two strings <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and another string called <span class=\"tex-span\"><i>virus</i></span>. Your task is to find the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span>, such that it doesn't contain <span class=\"tex-span\"><i>virus</i></span> as a substring.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input contains three strings in three separate lines: <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and <span class=\"tex-span\"><i>virus</i></span> (<span class=\"tex-span\">1 ≤ |<i>s</i><sub class=\"lower-index\">1</sub>|, |<i>s</i><sub class=\"lower-index\">2</sub>|, |<i>virus</i>| ≤ 100</span>). Each string consists only of uppercase English letters.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> without <span class=\"tex-span\"><i>virus</i></span> as a substring. If there are multiple answers, any of them will be accepted. </p><p>If there is no valid common subsequence, output 0.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>AJKEQSLOBSROFGZ<br/>OVGURWZLWVLUXTH<br/>OZ<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>ORZ<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>AA<br/>A<br/>A<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"17630f43285802b8f4be63b000773c14\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"76ca6f0bbc2c68c0c469d82a1a1c06e9e639f443\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='17630f43285802b8f4be63b000773c14'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F346%2Fproblem%2FB%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='17630f43285802b8f4be63b000773c14'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/346\">Codeforces Round 201 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='17630f43285802b8f4be63b000773c14'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/346/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Prefix- and Z-functions, suffix structures, Knuth–Morris–Pratt algorithm, etc\">\r\n strings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2000\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='17630f43285802b8f4be63b000773c14'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3504\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='17630f43285802b8f4be63b000773c14'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3504\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8896\" title=\"Codeforces Round #201\" target=\"_blank\">Codeforces Round #201</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1860:1861\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8903\" title=\"Codeforces Round #201 Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1864\" resourceName=\"Codeforces Round #201 Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/346\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/346/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/346/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/346/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/346/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/346/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/346/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/346/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_94e9d36d194ddb193eb11bb4e0ca659fe309f2cf\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Lucky Common Subsequence</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>3 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>512 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>In mathematics, a <span class=\"tex-font-style-it\">subsequence</span> is a sequence that can be derived from another sequence by deleting some elements without changing the order of the remaining elements. For example, the sequence <span class=\"tex-font-style-tt\">BDF</span> is a subsequence of <span class=\"tex-font-style-tt\">ABCDEF</span>. A <span class=\"tex-font-style-it\">substring</span> of a string is a continuous subsequence of the string. For example, <span class=\"tex-font-style-tt\">BCD</span> is a substring of <span class=\"tex-font-style-tt\">ABCDEF</span>.</p><p>You are given two strings <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and another string called <span class=\"tex-span\"><i>virus</i></span>. Your task is to find the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span>, such that it doesn't contain <span class=\"tex-span\"><i>virus</i></span> as a substring.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input contains three strings in three separate lines: <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and <span class=\"tex-span\"><i>virus</i></span> (<span class=\"tex-span\">1 ≤ |<i>s</i><sub class=\"lower-index\">1</sub>|, |<i>s</i><sub class=\"lower-index\">2</sub>|, |<i>virus</i>| ≤ 100</span>). Each string consists only of uppercase English letters.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> without <span class=\"tex-span\"><i>virus</i></span> as a substring. If there are multiple answers, any of them will be accepted. </p><p>If there is no valid common subsequence, output 0.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>AJKEQSLOBSROFGZ<br />OVGURWZLWVLUXTH<br />OZ<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>ORZ<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>AA<br />A<br />A<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:48</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bdcb4e529d87',t:'MTY5NjY0NjAyOC4xMjkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Dynamic programming\", \"Prefix- and Z-functions, suffix structures, Knuth\\u2013Morris\\u2013Pratt algorithm, etc\"]"},"short_tags":{"kind":"string","value":"[\"dp\", \"strings\", \"*2000\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8903"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"1c88316eb9ff5851524d80ea59ef3f32\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #201 Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #201 Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='1c88316eb9ff5851524d80ea59ef3f32'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8903\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/MinakoKojima\">MinakoKojima</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/MinakoKojima\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/MinakoKojima\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/MinakoKojima\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/MinakoKojima\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/MinakoKojima\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/MinakoKojima\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/MinakoKojima\" style=\"text-decoration:none;color:black !important;\">MinakoKojima's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8958\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8903\"> <p>Codeforces Round #201 Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a>,\r\n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><img alt=\" \" src=\"/predownloaded/41/3f/413f7303374a112dddc1e63e29cfc12924514cd7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><h1>Overview</h1><p>In DIV 1, there are 4 interesting problems together with a normal one. We think it is reasonable because we can't have a round fullly with intelligence. Problem A, C have weak pretests while others intended to be strong. About more then 200 participants solve A in the early 45mins, then a few of them start from C while most of the other start from B. </p><p>Problem B is a rather standard problem, but if you're unfamiliar with the algorithm, it can be very hard. Problem C is a more intersting problem. As the name implies, there was <a href=\"//codeforces.com/problemset/problem/251/C\">a similar version</a> in the previous round before, but this time it has a brand new constrains.(So here we have a psychology experiment: could different constrains make people thinking in a slightly different way?ww)</p><p>The standard solution of problem C is <span class=\"tex-span\"><i>O</i>((<i>b</i> - <i>a</i>) + <i>nlogn</i>)</span>. The first expected correct solution was written by <a class=\"rated-user user-orange\" href=\"/profile/zeliboba\" title=\"International Master zeliboba\">zeliboba</a>. <a href=\"//codeforces.com/contest/346/submission/4512654\">http://codeforces.com/contest/346/submission/4512654</a></p><p>After that, some people start to solve problem D. Problem D looks like a hard dp problem on a graph at the first glance, the key point is how to avoid the circle in the transfer equation. It turn out to be elegant after you could found a right order of the evaluation. Problem E is challenging which you need find a way to transform the original question into a smaller scale, and cut off many many corner cases ... And in the very end, you find a way like binary search to get <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span> as the time complexity. No one manage to solve problem E during the contest, maybe <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> is the man who closest to it.</p><p>The winner comes to <a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"Grandmaster cgy4ever\">cgy4ever</a>, because he found the draw-black in his previous C submission during the very beginning even when there is nobody hack him! He resubmit it decisively and get back when finished problem D. After that, he use the same trick which made him failed before to hack others and got a handsomely rewards. The second place went to <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a>, because of the combination of decent speed in A, B, C, D.</p><p>Problem B belongs to me, problem C belongs to <a class=\"rated-user user-violet\" href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\">CMHJT</a> and others belong to <a class=\"rated-user user-orange\" href=\"/profile/UESTC_Nocturne\" title=\"International Master UESTC_Nocturne\">UESTC_Nocturne</a>. The illustrator of problem C is <a href=\"http://www.pixiv.net/member_illust.php?mode=medium&illust_id=38602657\">Chairman Miao(貓主席)</a>.</p><h1>Editorial</h1><h3><a href=\"//codeforces.com/problemset/problem/346/A\">Problem A. Alice and Bob</a></h3><h4>Brief description:</h4><p>Alice and Bob play a game, the rules are as follows: First, they will get a set of <span class=\"tex-span\"><i>n</i></span> distinct numbers. And then they take turns to do the following operations. During each operation, either Alice or Bob can choose two different numbers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> from the set, as long as <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> is not in the set, then they add it to the set. The person who can not choose two numbers successfully will lose the game. The question is who will finally win the game if both of them do operations optimally. Remember that Alice always goes first.</p><h4>Analysis:</h4><p>First, no matter what happend, the number set we get at the very endding will be same all the time. Let's say <span class=\"tex-span\"><i>d</i> = <i>gcd</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}. Then the set in the endding will be some things like {<span class=\"tex-span\"><i>d</i></span>, <span class=\"tex-span\">2<i>d</i></span>, <span class=\"tex-span\">3<i>d</i></span>, ... <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}}. So there is always <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub>} / <i>d</i></span> — <span class=\"tex-span\"><i>n</i></span> rounds. And what we should do rest is to check the parity of this value.</p><h3><a href=\"//codeforces.com/problemset/problem/346/B\">Problem B. Lucky Common Subsequence</a></h3><h4>Brief description:</h4><p>You have been given two strings <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and <span class=\"tex-span\"><i>virus</i></span>, and you have to find the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> without <span class=\"tex-span\"><i>virus</i></span> as a substring.</p><h4>Analysis:</h4><p>This is a rather classical problem, let's say if there is no virus, then it is the classical **LCS ** problem. You can solve this by a <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> dynamic programing.</p><p>When consider about the virus, we should add 1 more dimension on the state to trace the growth of the virus. It can be done by wheather <strong>Aho-Corasick automation</strong>, or <strong>KMP</strong> when there is only one virus in this case. The overall time complexity is <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">3</sup>)</span>.</p><h3><a href=\"//codeforces.com/problemset/problem/346/C\">Problem C. Number Transformation II</a></h3><h4>Brief description:</h4><p>You have a number <span class=\"tex-span\"><i>b</i></span>, and want to minus it to <span class=\"tex-span\"><i>a</i></span>, what you can do in each step is weather subtract 1 or <span class=\"tex-span\"><i>b</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> from <span class=\"tex-span\"><i>b</i></span>. And we ask what is the minimum number of steps you need.</p><h4>Analysis:</h4><p>I bet there is a few people know the greedy method even if he/she have solved the early version before.</p><p><a href=\"//codeforces.com/problemset/problem/251/C\">Codeforces #153 Div 1. Problem C. Number Transformation</a></p><p>Let dp[k] denotes the minimum number of steps to transform b+k to b. In each step, you could only choose i which makes b+k-(b+k) mod x[i] minimal to calc dp[k]. It works bacause dp[0..k-1] is a monotone increasing function. Proof: - Say dp[k]=dp[k-t]+1.If t==1, then dp[0..k] is monotone increasing obviously.Otherwise dp[k-1]<=dp[k-t]+1=dp[k] (there must exist a x[i] makes b+k-1 also transform to b+k-t,and it is not necessarily the optimal decision of dp[k-1]). So dp[k] is a monotone increasing function, we can greedily calc dp[a-b].</p><p>In the first glance, it looks like something which will run in square complexity. But actually is linear. That is because, we could cut exactly max{<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>} in each 2 step. It can be proof by induction.</p><p>So the remians work is to delete those same <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>, and watch out some situation could cause degeneration. Many of us failed in this last step and got <strong>TLE</strong></p><h3><a href=\"//codeforces.com/problemset/problem/346/D\">Problem D. Robot Control</a></h3><p>Let's dp from t to s.</p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>Here dp[u] means, the minimum number of orders mzry1992 needs to send in the worst case. The left-hand-side is sending order while the right-hand side is not. At the beginning, we have dp[t] = 1, and dp[s] will be the answer.</p><p>We can see there is circular dependence in this equation, in this situation, one standard method is using Bellman-Ford algorithm to evaluate the dp function.</p><p>But it is not appropriate for this problem.</p><p>(In fact, we add a part of targeted datas in pretest, these datas are enough to block most of our <a href=\"https://en.wikipedia.org/wiki/Bellman%E2%80%93Ford_algorithm\">Bellman-Ford algorithm</a>, although there is still a few participator can get accepted by Bellman-Ford algorithm during the contest.</p><p>Check <a class=\"rated-user user-violet\" href=\"/profile/rares.buhai\" title=\"Candidate Master rares.buhai\">rares.buhai</a>'s <a href=\"//codeforces.com/contest/346/submission/4520171\">solution</a></p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>The expected solution is evaluating the dp function as the increased value of dp[u] itself. Further analysis shows, wheather we decided sending order or not in u can be judged as the out-degree of u.</p> <pre><code><br />while (!Q.empty()) {\n u = Q.front(), Q.pop_front()\n for each edge from v to u\n --out_degree[v]\n\tif (out_degree[v] == 0) {\n relax dp[v] by dp[u]\n if success, add v to the front of Q\n\t}\n\telse{\n\t relax dp[v] by dp[u] + 1\n\t if success, add v to the back of Q\n }\t\n }\n</code></pre><p>Check <a class=\"rated-user user-orange\" href=\"/profile/Ra16bit\" title=\"International Master Ra16bit\">Ra16bit</a>'s <a href=\"//codeforces.com/contest/346/submission/4519668\">solution</a> to see how it works.</p><h3><a href=\"//codeforces.com/problemset/problem/346/E\">Problem E. Doodle Jump</a></h3><h4>Brief description:</h4><p>You have been give <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>, <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>h</i></span> (gcd(<span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>) = 1), For each <span class=\"tex-span\"><i>ai</i></span> mod <span class=\"tex-span\"><i>p</i></span>, (<span class=\"tex-span\"><i>i</i></span>∈[1, n]), check weather the maximum distance in neighborhood after sorting is <= <span class=\"tex-span\"><i>h</i></span>. </p><h4>Analysis:</h4><p>Take <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 for example ... Divided the numbers in group.</p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 18\n</code></pre><p>We start a new group when the number > P</p><p>We found the difference between the elements of the first group is 5, The subsequent is filling some gap between the them ...</p><p>After some observation we could found that we should only consider into one gap ...(e.g. [0, 5] or [15, 20] or [20, 25] ... ) </p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>That says .. <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 is roughly equal to some things in small scale?</p><p>So let's check it in detail. Lemma 1. In any case, the gap after 20 won't better than any gap before it.</p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>For example, in this case, the gap after 20 is: 20, 22 And it has 16 in [15, 17] but no 21. </p><p>Is there any chance that [20, 23] is better than [15, 20]?</p><p>No, that is because, when there is no 21, then (19+5)%23 = 1, go to next floor. and there is no corresponding gap after 20 ([22, 24]) for this gap ([17, 19])</p><p>So we only need to consider [15, 20] ... and we found [15, 20] is roughly equal to [0, 5]</p> <pre><code>e.g. : 15 20 17 19 16 18 \nequal: 0 5 2 4 1 3\n</code></pre><p>we say 'roughly' because we havn't check some boundary case like there is 3 but on 18 ... </p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 \n</code></pre><p>If it happend, we should remove the number 3. .. If we can remove the element 5, then we can from a=5, p=23 to a'=2, p'=5 ...(n' = an/p, a' = a-p%a, if there is 3 but no 18, n'=n'-1)</p><p>The rest things is to discuss wheather 5 is necessary or not.</p><p>Let's we have:</p> <pre><code>0 2 4\n1 3\n</code></pre><p>If the 2*n'<5, then there is only one floor, the answer is max(2, 5-2*n'). If there is more than one floor, we could conclude that 5 is useless.</p><p>Proof: Elemets in 1st floor is: </p> <pre><code>0 a 2a 3a ...\n</code></pre><p>Let's say the maximum elements in 1st floor is x, then the minimum element in the 2nd floor is b0 = x+a-p, because b0 — a = x-p, so the difference between b0 and a is equal to the difference between x and p. That is, we can consider [b0, a] rather than [x, p], when there is a element insert in [b0, a], there must be some element insert in [x, p] in the same position.</p><p>So we have have succeeded to transform our original problem into a small one. Of couse, this problem havn't been solved, we haven't consider the time complexity. Says a' = a — p%a, when p = a+1, then a' = a-1, but we have <span class=\"tex-span\"><i>a</i></span> equal to 10^9, it won't work.</p><p>But, let's we have A1, A2, ... An ... and we subtract <span class=\"tex-span\"><i>d</i></span> from all of them, the answer won't be changed. So we can use p%a substitute for a-p%a, this is equivalent to we subtract %p% from all of them ...</p><p>So we set a' = min(a-p%a, p%a), so a'<=a/2, therefore, the final time complexity is <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span>.</p><p>You can check <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> <a href=\"//codeforces.com/contest/346/submission/4523388\">'s solution</a> for detail.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/346\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/347\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-4906-8958\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"4906\",\n blogEntryId: \"8903\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+56</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/MinakoKojima\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/MinakoKojima\">\n MinakoKojima\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8903#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8903#comments\">\n 66\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8974\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (56)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146290\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mohammadrdeh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/47/avatar/91eee3f7a5ec41f6.jpg'/> </a>\n <div><a href=\"/profile/mohammadrdeh\" title=\"Specialist mohammadrdeh\" class=\"rated-user user-cyan\">mohammadrdeh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146290\" href=\"?#comment-146290\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146290\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"14\"\r\n data-commentUserId=\"47\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+14</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146290\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>there is a typo: "... the classical <strong>LCA</strong> problem ..." => <strong>LCS</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146290 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146290 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146290\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146291\" commentParentId=\"146290\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146291\" href=\"?#comment-146291\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146290\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146291\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146291\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you. Fixed. m(_ _)m</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146291 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146291 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146291\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146297\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 05:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146297\" href=\"?#comment-146297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Actually our standard solution to C is O(b-a+n). O(b-a+n),O(b-a+nlogn),O((b-a+n)logn) are all able to pass during the test.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146297\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146335\" commentParentId=\"146297\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mmaxio\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/486/avatar/4bb53c24fc9e4c1.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/mmaxio\" title=\"International Master mmaxio\" class=\"rated-user user-orange\">mmaxio</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 17:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146335\" href=\"?#comment-146335\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146297\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146335\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146335\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"486\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146335\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>oh, never mind</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146335 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146335 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146335\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146299\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shashwat.gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6204/avatar/67f8e17c53f70578.jpg'/> </a>\n <div><a href=\"/profile/shashwat.gupta\" title=\"Specialist shashwat.gupta\" class=\"rated-user user-cyan\">shashwat.gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146299\" href=\"?#comment-146299\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146299\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"6204\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146299\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Problem B: Can you Explain little bit more on How "Aho-Corasick automation, or KMP" can help in figuring out smallest string that does not contain virus.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146299 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146299 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146299\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146300\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146300\" href=\"?#comment-146300\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146300\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146300\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For B, I already had the intuitive idea that this problem will be solved by either Aho-Corasick algorithm or KMP with dp, but I could not formalize the idea of states transition in dp. Could you please just provide the state in your dp algorithm?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146300 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146300 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146300\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146354\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146354\" href=\"?#comment-146354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146354\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Original problem can be solved by dp with two parameters DP[Len(s)] [Len(t)]. <a href=\"https://en.wikipedia.org/wiki/Longest_common_subsequence_problem\">http://en.wikipedia.org/wiki/Longest_common_subsequence_problem</a></p><p>To solve B you need to modificate it to DP[Len(s)][Len(t)][Len(virus)-1] where third parameter means maximum length of suffix of LCS that equal to prefix of virus.</p><p>To easy check where we go from K state (third parameter) by character C we can make automat on prefix function by virus.</p><p>Then if we stand in DP[i][j][k] :<br /> 1) if(s[i] == t[j] and Automat[k][c]<Len(virus) we try to relax DP[i+1][j+1][Automat[k][c]]<br /> 2) Try to relax DP[i][j+1][k] and DP[i+1][j][k]</p><p><strong>UPD</strong> My solution: <a href=\"//codeforces.com/contest/346/submission/4532899\">http://codeforces.com/contest/346/submission/4532899</a> (hope it understandable)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146354\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146357\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146357\" href=\"?#comment-146357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>got it, many thanks to you man :) Also understood why KMP tag mentioned in the problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146357\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146493\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lama\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/72190/avatar/735906a91d1576e3.jpg'/> </a>\n <div><a href=\"/profile/lama\" title=\"Expert lama\" class=\"rated-user user-blue\">lama</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 18:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146493\" href=\"?#comment-146493\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146493\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146493\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) Can you please explain what "maximum length of suffix of LCS that equal to prefix of virus" means? 2) What is an automat?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146493 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146493 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146493\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146519\" commentParentId=\"146493\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/25/2013 05:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146519\" href=\"?#comment-146519\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146493\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146519\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146519\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146519\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) We stand in DP[i][j][k]-state (in which we store longest LCS), virus = "virus" <br /> Let's go from k = 0 to 4,then:</p> <pre><code>0) DP[i][j][0] means that finded LCS not ends on "v" or "vi" or "vir" or "viru" or "virus". (example: "a")\n\n1) DP[i][j][1] means that finded LCS ends on "v", but not on "vi" or "vir" or "viru" or "virus". (example: "av")\n\n2) DP[i][j][2] means that finded LCS ends on "vi", but not on "vir" or "viru" or "virus". (example: "avi")\t\n\n3) DP[i][j][3] means that finded LCS ends on "vir", but not on "viru" or "virus". (example: "avir")\n\n4) DP[i][j][4] means that finded LCS ends on "viru", but not on "virus". (example: "aviru")\n\nWe take "longest suffix of LCS that equal prefix of virus", because virus could be: "vvvvv" or "ababv" (and infinite others)\n If LCS = "avvv" - it ends on "v","vv","vvv". (virus = "vvvvv")\n If LCS = "aabab" - it ends on "ab" and "abab". (virus = "ababv")\n</code></pre><p><a href=\"https://en.wikipedia.org/wiki/Knuth%E2%80%93Morris%E2%80%93Pratt_algorithm\">KMP</a></p><p>2) <a href=\"https://en.wikipedia.org/wiki/Automata_theory\">http://en.wikipedia.org/wiki/Automata_theory</a></p><p>Can't find nothing about automaton on prefix-function in english. I hope you will be able understand <a href=\"http://e-maxx.ru/algo/prefix_function\">this</a> with some translator (google translate for example).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146519 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146519 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146519\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"551712\" commentParentId=\"146519\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/srv_twry\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/447741/avatar/d1a80b00eb029c2b.jpg'/> </a>\n <div><a href=\"/profile/srv_twry\" title=\"Expert srv_twry\" class=\"rated-user user-blue\">srv_twry</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/19/2019 12:58\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-551712\" href=\"?#comment-551712\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146519\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"551712\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"447741\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-551712\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Fortunately, the e-maxx article on Prefix function has been translated in English and can be found here: <a href=\"https://cp-algorithms.com/string/prefix-function.html#toc-tgt-12\">prefix-function: automaton on prefix-function</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-551712 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-551712 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-551712\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"768401\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ttbbnnn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1694563/avatar/ff85df0301cf6f76.jpg'/> </a>\n <div><a href=\"/profile/ttbbnnn\" title=\"Master ttbbnnn\" class=\"rated-user user-orange\">ttbbnnn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2021 20:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-768401\" href=\"?#comment-768401\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"768401\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1694563\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-768401\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My solution for B got a WA on test 41 and I don't know why :<, please help me with this code: <a href=\"https://codeforces.com/contest/346/submission/109283664\">https://codeforces.com/contest/346/submission/109283664</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-768401 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-768401 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-768401\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146301\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146301\" href=\"?#comment-146301\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146301\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146301\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146301\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"So the remians work is to delete those same xi, and watch out some situation could cause degeneration. Many of us failed in this last step and got TLE", I really could not understand this. What you you mean by degeneration in this case? Please explain this last important step.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146301 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146301 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146301\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146302\" commentParentId=\"146301\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:37\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146302\" href=\"?#comment-146302\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146301\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146302\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146302\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>suppose b=1, all x[i]>a, what will happen?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146302 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146302 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146302\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146304\" commentParentId=\"146302\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146304\" href=\"?#comment-146304\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146302\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146304\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146304\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As b = 1, All x[i] > a. Then a % x[i] = a. So if we take this, then we will lead to a — a = 0, which is less than b. So we need to move one by one, so answer would be a.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146304 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146304 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146304\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146309\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146309\" href=\"?#comment-146309\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146309\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146309\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Alice and Bob problem how do you prove that you will always get {d, 2d, 3d, ... max{xi}} in the end. It is easy to see but I am unable to prove it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146309 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146309 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146309\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146365\" commentParentId=\"146309\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marat.snowbear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98082/avatar/1499cf6d0c86172.jpg'/> </a>\n <div><a href=\"/profile/marat.snowbear\" title=\"International Master marat.snowbear\" class=\"rated-user user-orange\">marat.snowbear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146365\" href=\"?#comment-146365\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146309\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146365\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"98082\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146365\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I convinced myself like this:</p> <ol> <li>Prove that we will be able to get d by some sequence of subtractions.</li> <li>Prove that we will be able to generate {d, 2d, 3d, ...}</li> <li>Prove that we will not be able to get anything else except for { d, 2d, 3d, ... }</li> </ol><p>In details:</p> <ol> <li><p>See <a href=\"https://en.wikipedia.org/wiki/Euclidean_algorithm\">Euclidean algorithm for finding GCD</a>. If you will look into the description or code you will see that it does exactly what is asked in this problem — subtracts numbers one from another. And the result is GCD of original two numbers. So you can see that by some sequence of subtractions you can get GCD.</p></li> <li><p>If you already have d which GCD of all the numbers then you can easily fill all the gaps in { d, 2d, 3d, ..., max } sequence by starting subtracting d from { max, max — d, max — 2d, ... }. So you will get the intended set.</p></li> <li><p>You cannot subtract two numbers a and b which have GCD(a, b) = d and get result which won't be dividable by d. So if you start with set where every numbers can be divided by d then no matter what you subtract you will always have the result which is also dividable by d.</p></li> </ol></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146365 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146365 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146365\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146390\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 16:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146390\" href=\"?#comment-146390\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146390\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146390\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, got it. Thanks!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146390 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146390 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146390\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"774539\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/25/2021 20:24\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-774539\" href=\"?#comment-774539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"774539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-774539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-774539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-774539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-774539\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146310\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i_coder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i_coder\" title=\"Expert i_coder\" class=\"rated-user user-blue\">i_coder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146310\" href=\"?#comment-146310\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146310\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"41979\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146310\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Is this the final editorial (except the D problem) ? The explanations to problems B and C are very limited and not at all well elaborated.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146310 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146310 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146310\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146314\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146314\" href=\"?#comment-146314\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146314\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146314\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can you tell me that why the number of rounds in Problem A will be max(xi)/d-n ? How do you come to this point ? can you please tell me this as am not to figure out this thing ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146314 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146314 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146314\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146316\" commentParentId=\"146314\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:45\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146316\" href=\"?#comment-146316\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146314\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146316\" revisionCount=\"7\" revision=\"7\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">7</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146316\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146316\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>take example <br /> 3 9 54 <br /> gcd (3, 9, 54) = 3 <br /> Now total rounds possible including (3, 9, 54) =<br />all multiples of 3 upto 54 <br /> 3, 6, 9, 12, 15, 18 ... 54 <br /> </p><p>So total count of these numbers = 54 / 3 = 18. <br /> </p><p>Now as out of these numbers 3 numbers are already taken, so subtract 3 <br /> so rounds remaining = 18 — 3 = 15 </p><p>Now it is very easy to generalize for 3 being d and 54 being n</p><p>answer would be n / d — n. <br /> I hope it is clear now :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146316 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146316 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146316\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146319\" commentParentId=\"146316\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146319\" href=\"?#comment-146319\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146316\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146319\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146319\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes, it is more clear to me now. but one thing is that how did you approach to gcd thing ? I understood the problem, the logic and all. how did you approach that it will be done using gcd thing and all ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146319 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146319 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146319\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146322\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146322\" href=\"?#comment-146322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146322\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My Ideas during solving the problem: <br /> all the examples had gcd 1. So I directly thought answer as max(xi) — n. <br /> But I thought it can not be too simple, I need to think more. <br /> So I took a case 2 4 6, I immediately found I am wrong in this case. <br /> Then the idea came into mind that if gcd of numbers is g. then we can not create any number not divisible by g because (g *k1 — k * k2) = g * (k1 — k2). </p><p>So Finally I coded it and got accpeted :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146322\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146338\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 19:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146338\" href=\"?#comment-146338\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146338\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146338\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>given the numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>, what is the minimum positive value you can achieve by combining them? </p><p>Let's write down the equation: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>·<i>x</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub>·<i>x</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>n</i></sub>·<i>x</i><sub class=\"lower-index\"><i>n</i></sub> = <i>d</i></span>, where <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> are some unknown integers. </p><p>It is, as you can see, none other than linear Diophantine equation. And it is known there is no solutions if <span class=\"tex-span\"><i>d</i></span> is not a multiple of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span> </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146338 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146338 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146338\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146317\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/subway\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123924/avatar/706e86f587cbabf0.jpg'/> </a>\n <div><a href=\"/profile/subway\" title=\"Expert subway\" class=\"rated-user user-blue\">subway</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146317\" href=\"?#comment-146317\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146317\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146317\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@hellodear-the final set will contain all elements {d,2d,3d,..max(Xi)} (d=gcd of all elements) so total no. of elements in final set =max(Xi)/d since initially we have 'n' elements total no. of new elements to be added in set to make it complete=(max(Xi)/d)-n.. hope this helps you..:)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146317 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146317 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146317\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146320\" commentParentId=\"146317\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146320\" href=\"?#comment-146320\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146317\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146320\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146320\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in this thing, I was applying some game theory, but it doesn't include anything like that. when the question says optimally, then how do you form examples so as to test your code on them ? because optimally means in the best they can. can you elaborate ? thanks to you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146320 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146320 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146320\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146324\" commentParentId=\"146320\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146324\" href=\"?#comment-146324\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146320\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146324\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146324\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146324\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>optimality argument is simple and also given in the editorial itself. <br /> As total you numbers finally would be {d, 2 * d,, .,, max (xi)}. <br /> Hence whatever you add to the these set, no other person will be able to add that as he has to add a new number everytime to this test. <br /> So outcome depend on the parity of turns.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146324 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146324 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146324\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146325\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sinamosavi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/87557/avatar/bde58fa97bcc5eb0.jpg'/> </a>\n <div><a href=\"/profile/sinamosavi\" title=\"Pupil sinamosavi\" class=\"rated-user user-green\">sinamosavi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146325\" href=\"?#comment-146325\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146325\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"87557\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146325\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the complete proof for A.Div1 is not that much straightforward. Maybe I'm making it too much difficult, but this is my complete proof:</p><p>First by induction, we prove that the numbers in the end will be <span class=\"tex-span\"><i>a</i>, 2<i>a</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Let <span class=\"tex-span\"><i>g</i> = <i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ... , <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span>. It's trivial that in the end <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>. Assume that <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>, because our numbers will be <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), 2<i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>, so we would have a new gcd. That's a contradiction, so <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) = <i>g</i></span> and our numbers will be <span class=\"tex-span\"><i>g</i>, 2<i>g</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Each move adds one number and in the end there will be <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e6ac12549498d8aaad3d63270d12497bc74a9f84.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> numbers, so the answer wil be the parity of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/48ba1bfd0fa315ab1595947b8e046b4cc211b908.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Sorry for my bad English.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146325 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146325 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146325\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146332\" commentParentId=\"146325\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146332\" href=\"?#comment-146332\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146325\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146332\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-13\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146332\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What about this test <code>2 3 5</code>? <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≠ <i>gcd</i></span></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146332 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146332 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146332\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146333\" commentParentId=\"146332\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146333\" href=\"?#comment-146333\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146332\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146333\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146333\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Oops. You've meant that <span class=\"tex-span\"><i>a</i></span> — is the result. Sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146333 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146333 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146333\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146334\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 16:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146334\" href=\"?#comment-146334\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146334\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146334\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146334\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>But how to prove that there is always a way to choose <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> while the number of the current round less than the maximum number of rounds? (Div2C)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146334 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146334 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146334\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146339\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:22\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146339\" href=\"?#comment-146339\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146339\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146339\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146339\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If gcd{xi}＝1, then for every xi there must exist ti to make sum｛xi*ti｝＝1. </p><p>(For example, x1＝5,x2＝7,then t1＝3,t2＝-2.x1*t1＋x2*t2＝1.)</p><p>And sum{xi*ti} can be performed in a few turns. ( (5-(7-5))-(7-5). )</p><p>And if we can get 1, then what number between [1,max{xi}] can't we get？</p><p>if gcd{xi}≠1.the proof is similar.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146339 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146339 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146339\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146341\" commentParentId=\"146339\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146341\" href=\"?#comment-146341\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146339\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146341\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146341\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why there is must exist such t[i]?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146341 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146341 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146341\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146366\" commentParentId=\"146341\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146366\" href=\"?#comment-146366\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146341\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146366\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146366\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You must know if gcd(a,b)＝1, there must exist x and y to make ax＋by＝1. It can be proved from this.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146366 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146366 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146366\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146376\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146376\" href=\"?#comment-146376\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146376\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146376\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146376\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So.. If we divide all the numbers by GCD, and after that a pair of coprime numbers have appeared, we always can reach 1. Let's choose coprime <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, then <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> will be also coprime with <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, and it will be less then <span class=\"tex-span\"><i>max</i>(<i>x</i>, <i>y</i>)</span>. So we can choose <span class=\"tex-span\"><i>mid</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>x</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>min</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>y</i><sub class=\"lower-index\">1</sub></span>, and they are coprime, and <span class=\"tex-span\">|<i>x</i><sub class=\"lower-index\">1</sub> - <i>y</i><sub class=\"lower-index\">1</sub>|</span> will be less than <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>. And etc. by induction. But what to do if there is not a pair of coprime numbers after dividing by GCD? For example <code>35 45 63</code>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146376 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146376 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146376\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146404\" commentParentId=\"146376\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146404\" href=\"?#comment-146404\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146376\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146404\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146404\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146404\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>63*2＋45*5＋35*(-10)＝1</p><p>Because gcd (35,45)＝5, we can consider 35 and 45 as one number 5x. Because gcd(5,63)＝1, so there must exist x,y to make 5x＋63y＝1.</p><p>So here comes a tragedy. We can get 5 first. Then we use this number together with 63 to make 1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146404 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146404 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146404\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146346\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KiAsaGibona\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/KiAsaGibona\" title=\"Specialist KiAsaGibona\" class=\"rated-user user-cyan\">KiAsaGibona</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 21:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146346\" href=\"?#comment-146346\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146346\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146346\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"99053\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146346\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Someone please explain the greedy idea of (Div 1 C) (Number Transformation II). Thanks in advance :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146346 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146346 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146346\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146367\" commentParentId=\"146346\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 09:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146367\" href=\"?#comment-146367\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146346\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146367\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146367\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's a pretty simple greedy idea: Just pick the <code>x</code> that makes the value of <code>a</code> smallest after applying the operation <code>a = a - a%x</code> (or subtract 1 if no choice for <code>x</code> makes <code>a</code> smaller). The proof why this works is given in the editorial: it is never better to get a larger number, so you should get the smallest one you can.</p><p>As listed on the last paragraph of the editorial you have to be careful to remove all <code>x</code> that are either duplicates or cannot be used anymore (<code>a - (a%x)</code> is smaller than <code>b</code>), otherwise you will get TLE.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146367 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146367 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146367\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146382\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146382\" href=\"?#comment-146382\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146382\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146382\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146382\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>how to find this x for each number?</p><p>we will iterate on all x[i]s and only delete x[i]s when x[i] > a?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146382 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146382 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146382\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146405\" commentParentId=\"146382\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146405\" href=\"?#comment-146405\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146382\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146405\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146405\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Iterate through all x[i]s and delete them when a — (a%x[i]) is smaller than b (if you only delete when x[i] > a, you will also get TLE).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146405 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146405 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146405\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146625\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 17:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146625\" href=\"?#comment-146625\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146625\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146625\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm really striving to understand why the algorithm turns out to be linear instead of quadratic... I know the editorial says "That is because, we could cut exactly <span class=\"tex-span\"><i>max</i>{<i>xi</i>}</span> in each 2 step.", but I can't really get what it means :\\</p><p>Can you give me a hint? Thanks :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146625 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146625 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146625\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146643\" commentParentId=\"146625\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/xenoslash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88090/avatar/f75f8cbc20d6133f.jpg'/> </a>\n <div><a href=\"/profile/xenoslash\" title=\"Expert xenoslash\" class=\"rated-user user-blue\">xenoslash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 19:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146643\" href=\"?#comment-146643\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146625\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146643\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146643\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"88090\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146643\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have an easy intuition of cutting at least max{xi} in O(1) steps, not sure what was the intended 2 step proofs though. I am going to use xi to refer to max{xi}, and assume that proper care is taken to only keep the relevant xi's.</p><p>When we do a-(a % xi), we bring caused a to be the next largest integer <= a that is a multiple of xi, since now new_a % xi = 0. Then, if a is divisible by xi, you can do.., do a-1 (causing it to be non-divisible by xi), then finally a-(a%xi) again. In this 3 step sequence you have brought a down to the next lower multiple of xi, and have essentially cut max{xi} in O(1) number of steps.</p><p>Sample code : <a href=\"//codeforces.com/contest/346/submission/4545367\">http://codeforces.com/contest/346/submission/4545367</a> Yeah I used tree set so it's not exactly O(n).. but hash set keeps giving me TLE :(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146643 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146643 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146643\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146689\" commentParentId=\"146643\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2013 12:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146689\" href=\"?#comment-146689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146643\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you very much, that was really eye-opening! This is why I love Codeforces, great community! :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146689\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146371\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Corvo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/11909/avatar/8404ac1aff5270ec.jpg'/> </a>\n <div><a href=\"/profile/Corvo\" title=\"Pupil Corvo\" class=\"rated-user user-green\">Corvo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 12:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146371\" href=\"?#comment-146371\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146371\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"11909\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146371\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please explain why the problem is solved through the GDC (A)? I tried like <a href=\"https://codeforces.com/contest/347/submission/4535232\">this</a>, but I still can not understand why you can not do. Please give a short test on which the decision falls. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146371 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146371 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146371\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146375\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146375\" href=\"?#comment-146375\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146375\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146375\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><pre><code>3\n14 4 2\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146375 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146375 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146375\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146378\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akashdeep\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/39866/avatar/6f66d1bbe26ef4ca.jpg'/> </a>\n <div><a href=\"/profile/akashdeep\" title=\"International Master akashdeep\" class=\"rated-user user-orange\">akashdeep</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146378\" href=\"?#comment-146378\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146378\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"39866\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146378\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Because only those numbers are possible in the game which are multiple of gcd. See this simplest test case</p> <pre><code>2\n4 6\n</code></pre><p>The only number possible in the game is (6-4) i.e. 2, but in your code u are assuming that somehow these (1,2,3,5) numbers can be obtained which is a wrong assumption.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146378 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146378 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146378\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146408\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/NegaTeeF\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/NegaTeeF\" title=\"Master NegaTeeF\" class=\"rated-user user-orange\">NegaTeeF</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 20:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146408\" href=\"?#comment-146408\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146408\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"65829\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146408\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Explain please, how to do Div1-D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146408 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146408 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146408\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146410\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/irakli_p\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29034/avatar/d879a3156498c6c7.jpg'/> </a>\n <div><a href=\"/profile/irakli_p\" title=\"Expert irakli_p\" class=\"rated-user user-blue\">irakli_p</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 21:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146410\" href=\"?#comment-146410\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146410\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29034\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146410\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i didn't understand Div 2 — D can someone explain it to me please </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146410 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146410 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146410\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146443\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/suiyuan2009\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49923/avatar/9065a92c0b30b883.jpg'/> </a>\n <div><a href=\"/profile/suiyuan2009\" title=\"Master suiyuan2009\" class=\"rated-user user-orange\">suiyuan2009</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 13:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146443\" href=\"?#comment-146443\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146443\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49923\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146443\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>problem B,ac automachine is doing the thing that belong to kmp</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146443 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146443 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146443\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146452\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 17:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146452\" href=\"?#comment-146452\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146452\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146452\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div1_E: Should the "Doodler" jump over the platform which H = P ? I just confused about that.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146452 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146452 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146452\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146480\" commentParentId=\"146452\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 11:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146480\" href=\"?#comment-146480\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146452\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146480\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146480\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OK I got the answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146480 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146480 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146480\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146463\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146463\" href=\"?#comment-146463\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146463\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"44\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+44</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146463\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>still waiting for D tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146463 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146463 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146463\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147566\" commentParentId=\"146463\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/05/2013 05:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147566\" href=\"?#comment-147566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146463\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>.. Update .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147566\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"235917\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/saurabhverma\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/143428/avatar/48808a8d5db775d4.jpg'/> </a>\n <div><a href=\"/profile/saurabhverma\" title=\"Expert saurabhverma\" class=\"rated-user user-blue\">saurabhverma</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2015 20:05\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-235917\" href=\"?#comment-235917\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"235917\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"143428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-235917\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In my approach to problem div1 B, I calculated longest common subsequence, prepended virus to it, calculated the Z function and deleted every character which had z[i] >= virus.size(). I don't think my approach is wrong. Can someone tell me if my code is wrong or the approach has some flaw. Thanks. Submission : <a href=\"//codeforces.com/contest/346/submission/11491420\">http://codeforces.com/contest/346/submission/11491420</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-235917 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-235917 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-235917\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"530287\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arpit4427\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/717924/avatar/90dcbc94a1e57cf.jpg'/> </a>\n <div><a href=\"/profile/arpit4427\" title=\"Expert arpit4427\" class=\"rated-user user-blue\">arpit4427</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/26/2019 14:04\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-530287\" href=\"?#comment-530287\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"530287\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"530287\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"717924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-530287\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone explain how to solve this problem <a href=\"/contest/346/problem/B\" title=\"Codeforces Round 201 (Div. 1)\">346B - Lucky Common Subsequence</a>? I have went thorugh the editorial but I could not understand.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-530287 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-530287 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-530287\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8974\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8974 = true;\r\nvar lastPreviewContent8974 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8974] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8974] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:24</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812874998e81759f',t:'MTY5NjcwNTk0NS4wMjkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1749,"cells":{"problem_id":{"kind":"string","value":"346C"},"contest":{"kind":"string","value":"346"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Number Transformation II"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Number Transformation II</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are given a sequence of positive integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> and two non-negative integers <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span>. Your task is to transform <span class=\"tex-span\"><i>a</i></span> into <span class=\"tex-span\"><i>b</i></span>. To do that, you can perform the following moves:</p><ul> <li> subtract 1 from the current <span class=\"tex-span\"><i>a</i></span>; </li><li> subtract <span class=\"tex-span\"><i>a</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ <i>n</i>)</span> from the current <span class=\"tex-span\"><i>a</i></span>. </li></ul><p>Operation <span class=\"tex-span\"><i>a</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> means taking the remainder after division of number <span class=\"tex-span\"><i>a</i></span> by number <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>Now you want to know the minimum number of moves needed to transform <span class=\"tex-span\"><i>a</i></span> into <span class=\"tex-span\"><i>b</i></span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a single integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup></span>). The second line contains <span class=\"tex-span\"><i>n</i></span> space-separated integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">2 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>). The third line contains two integers <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span> (<span class=\"tex-span\">0 ≤ <i>b</i> ≤ <i>a</i> ≤ 10<sup class=\"upper-index\">9</sup></span>, <span class=\"tex-span\"><i>a</i> - <i>b</i> ≤ 10<sup class=\"upper-index\">6</sup></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the required minimum number of moves needed to transform number <span class=\"tex-span\"><i>a</i></span> into number <span class=\"tex-span\"><i>b</i></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>3 4 5<br/>30 17<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>5 6 7<br/>1000 200<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>206<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"da636cb4a3c2f7d26044e4964949e74d\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"76ca6f0bbc2c68c0c469d82a1a1c06e9e639f443\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='da636cb4a3c2f7d26044e4964949e74d'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F346%2Fproblem%2FC%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='da636cb4a3c2f7d26044e4964949e74d'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/346\">Codeforces Round 201 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='da636cb4a3c2f7d26044e4964949e74d'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/346/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2200\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='da636cb4a3c2f7d26044e4964949e74d'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3505\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='da636cb4a3c2f7d26044e4964949e74d'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3505\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8896\" title=\"Codeforces Round #201\" target=\"_blank\">Codeforces Round #201</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1860:1861\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8903\" title=\"Codeforces Round #201 Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1864\" resourceName=\"Codeforces Round #201 Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/346\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/346/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/346/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/346/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/346/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/346/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/346/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/346/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_2fd79b650a628b9b7146d069bcdfd676730fdb98\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Number Transformation II</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are given a sequence of positive integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> and two non-negative integers <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span>. Your task is to transform <span class=\"tex-span\"><i>a</i></span> into <span class=\"tex-span\"><i>b</i></span>. To do that, you can perform the following moves:</p><ul> <li> subtract 1 from the current <span class=\"tex-span\"><i>a</i></span>; </li><li> subtract <span class=\"tex-span\"><i>a</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ <i>n</i>)</span> from the current <span class=\"tex-span\"><i>a</i></span>. </li></ul><p>Operation <span class=\"tex-span\"><i>a</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> means taking the remainder after division of number <span class=\"tex-span\"><i>a</i></span> by number <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>Now you want to know the minimum number of moves needed to transform <span class=\"tex-span\"><i>a</i></span> into <span class=\"tex-span\"><i>b</i></span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a single integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup></span>). The second line contains <span class=\"tex-span\"><i>n</i></span> space-separated integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">2 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>). The third line contains two integers <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span> (<span class=\"tex-span\">0 ≤ <i>b</i> ≤ <i>a</i> ≤ 10<sup class=\"upper-index\">9</sup></span>, <span class=\"tex-span\"><i>a</i> - <i>b</i> ≤ 10<sup class=\"upper-index\">6</sup></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the required minimum number of moves needed to transform number <span class=\"tex-span\"><i>a</i></span> into number <span class=\"tex-span\"><i>b</i></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />3 4 5<br />30 17<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />5 6 7<br />1000 200<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>206<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:49</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bdd36cc613b4',t:'MTY5NjY0NjAyOS40MzkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Greedy algorithms\", \"Mathematics including integration, differential equations, etc\"]"},"short_tags":{"kind":"string","value":"[\"greedy\", \"math\", \"*2200\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8903"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"1c88316eb9ff5851524d80ea59ef3f32\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #201 Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #201 Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='1c88316eb9ff5851524d80ea59ef3f32'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8903\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/MinakoKojima\">MinakoKojima</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/MinakoKojima\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/MinakoKojima\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/MinakoKojima\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/MinakoKojima\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/MinakoKojima\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/MinakoKojima\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/MinakoKojima\" style=\"text-decoration:none;color:black !important;\">MinakoKojima's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8958\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8903\"> <p>Codeforces Round #201 Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a>,\r\n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><img alt=\" \" src=\"/predownloaded/41/3f/413f7303374a112dddc1e63e29cfc12924514cd7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><h1>Overview</h1><p>In DIV 1, there are 4 interesting problems together with a normal one. We think it is reasonable because we can't have a round fullly with intelligence. Problem A, C have weak pretests while others intended to be strong. About more then 200 participants solve A in the early 45mins, then a few of them start from C while most of the other start from B. </p><p>Problem B is a rather standard problem, but if you're unfamiliar with the algorithm, it can be very hard. Problem C is a more intersting problem. As the name implies, there was <a href=\"//codeforces.com/problemset/problem/251/C\">a similar version</a> in the previous round before, but this time it has a brand new constrains.(So here we have a psychology experiment: could different constrains make people thinking in a slightly different way?ww)</p><p>The standard solution of problem C is <span class=\"tex-span\"><i>O</i>((<i>b</i> - <i>a</i>) + <i>nlogn</i>)</span>. The first expected correct solution was written by <a class=\"rated-user user-orange\" href=\"/profile/zeliboba\" title=\"International Master zeliboba\">zeliboba</a>. <a href=\"//codeforces.com/contest/346/submission/4512654\">http://codeforces.com/contest/346/submission/4512654</a></p><p>After that, some people start to solve problem D. Problem D looks like a hard dp problem on a graph at the first glance, the key point is how to avoid the circle in the transfer equation. It turn out to be elegant after you could found a right order of the evaluation. Problem E is challenging which you need find a way to transform the original question into a smaller scale, and cut off many many corner cases ... And in the very end, you find a way like binary search to get <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span> as the time complexity. No one manage to solve problem E during the contest, maybe <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> is the man who closest to it.</p><p>The winner comes to <a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"Grandmaster cgy4ever\">cgy4ever</a>, because he found the draw-black in his previous C submission during the very beginning even when there is nobody hack him! He resubmit it decisively and get back when finished problem D. After that, he use the same trick which made him failed before to hack others and got a handsomely rewards. The second place went to <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a>, because of the combination of decent speed in A, B, C, D.</p><p>Problem B belongs to me, problem C belongs to <a class=\"rated-user user-violet\" href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\">CMHJT</a> and others belong to <a class=\"rated-user user-orange\" href=\"/profile/UESTC_Nocturne\" title=\"International Master UESTC_Nocturne\">UESTC_Nocturne</a>. The illustrator of problem C is <a href=\"http://www.pixiv.net/member_illust.php?mode=medium&illust_id=38602657\">Chairman Miao(貓主席)</a>.</p><h1>Editorial</h1><h3><a href=\"//codeforces.com/problemset/problem/346/A\">Problem A. Alice and Bob</a></h3><h4>Brief description:</h4><p>Alice and Bob play a game, the rules are as follows: First, they will get a set of <span class=\"tex-span\"><i>n</i></span> distinct numbers. And then they take turns to do the following operations. During each operation, either Alice or Bob can choose two different numbers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> from the set, as long as <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> is not in the set, then they add it to the set. The person who can not choose two numbers successfully will lose the game. The question is who will finally win the game if both of them do operations optimally. Remember that Alice always goes first.</p><h4>Analysis:</h4><p>First, no matter what happend, the number set we get at the very endding will be same all the time. Let's say <span class=\"tex-span\"><i>d</i> = <i>gcd</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}. Then the set in the endding will be some things like {<span class=\"tex-span\"><i>d</i></span>, <span class=\"tex-span\">2<i>d</i></span>, <span class=\"tex-span\">3<i>d</i></span>, ... <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}}. So there is always <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub>} / <i>d</i></span> — <span class=\"tex-span\"><i>n</i></span> rounds. And what we should do rest is to check the parity of this value.</p><h3><a href=\"//codeforces.com/problemset/problem/346/B\">Problem B. Lucky Common Subsequence</a></h3><h4>Brief description:</h4><p>You have been given two strings <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and <span class=\"tex-span\"><i>virus</i></span>, and you have to find the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> without <span class=\"tex-span\"><i>virus</i></span> as a substring.</p><h4>Analysis:</h4><p>This is a rather classical problem, let's say if there is no virus, then it is the classical **LCS ** problem. You can solve this by a <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> dynamic programing.</p><p>When consider about the virus, we should add 1 more dimension on the state to trace the growth of the virus. It can be done by wheather <strong>Aho-Corasick automation</strong>, or <strong>KMP</strong> when there is only one virus in this case. The overall time complexity is <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">3</sup>)</span>.</p><h3><a href=\"//codeforces.com/problemset/problem/346/C\">Problem C. Number Transformation II</a></h3><h4>Brief description:</h4><p>You have a number <span class=\"tex-span\"><i>b</i></span>, and want to minus it to <span class=\"tex-span\"><i>a</i></span>, what you can do in each step is weather subtract 1 or <span class=\"tex-span\"><i>b</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> from <span class=\"tex-span\"><i>b</i></span>. And we ask what is the minimum number of steps you need.</p><h4>Analysis:</h4><p>I bet there is a few people know the greedy method even if he/she have solved the early version before.</p><p><a href=\"//codeforces.com/problemset/problem/251/C\">Codeforces #153 Div 1. Problem C. Number Transformation</a></p><p>Let dp[k] denotes the minimum number of steps to transform b+k to b. In each step, you could only choose i which makes b+k-(b+k) mod x[i] minimal to calc dp[k]. It works bacause dp[0..k-1] is a monotone increasing function. Proof: - Say dp[k]=dp[k-t]+1.If t==1, then dp[0..k] is monotone increasing obviously.Otherwise dp[k-1]<=dp[k-t]+1=dp[k] (there must exist a x[i] makes b+k-1 also transform to b+k-t,and it is not necessarily the optimal decision of dp[k-1]). So dp[k] is a monotone increasing function, we can greedily calc dp[a-b].</p><p>In the first glance, it looks like something which will run in square complexity. But actually is linear. That is because, we could cut exactly max{<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>} in each 2 step. It can be proof by induction.</p><p>So the remians work is to delete those same <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>, and watch out some situation could cause degeneration. Many of us failed in this last step and got <strong>TLE</strong></p><h3><a href=\"//codeforces.com/problemset/problem/346/D\">Problem D. Robot Control</a></h3><p>Let's dp from t to s.</p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>Here dp[u] means, the minimum number of orders mzry1992 needs to send in the worst case. The left-hand-side is sending order while the right-hand side is not. At the beginning, we have dp[t] = 1, and dp[s] will be the answer.</p><p>We can see there is circular dependence in this equation, in this situation, one standard method is using Bellman-Ford algorithm to evaluate the dp function.</p><p>But it is not appropriate for this problem.</p><p>(In fact, we add a part of targeted datas in pretest, these datas are enough to block most of our <a href=\"https://en.wikipedia.org/wiki/Bellman%E2%80%93Ford_algorithm\">Bellman-Ford algorithm</a>, although there is still a few participator can get accepted by Bellman-Ford algorithm during the contest.</p><p>Check <a class=\"rated-user user-violet\" href=\"/profile/rares.buhai\" title=\"Candidate Master rares.buhai\">rares.buhai</a>'s <a href=\"//codeforces.com/contest/346/submission/4520171\">solution</a></p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>The expected solution is evaluating the dp function as the increased value of dp[u] itself. Further analysis shows, wheather we decided sending order or not in u can be judged as the out-degree of u.</p> <pre><code><br />while (!Q.empty()) {\n u = Q.front(), Q.pop_front()\n for each edge from v to u\n --out_degree[v]\n\tif (out_degree[v] == 0) {\n relax dp[v] by dp[u]\n if success, add v to the front of Q\n\t}\n\telse{\n\t relax dp[v] by dp[u] + 1\n\t if success, add v to the back of Q\n }\t\n }\n</code></pre><p>Check <a class=\"rated-user user-orange\" href=\"/profile/Ra16bit\" title=\"International Master Ra16bit\">Ra16bit</a>'s <a href=\"//codeforces.com/contest/346/submission/4519668\">solution</a> to see how it works.</p><h3><a href=\"//codeforces.com/problemset/problem/346/E\">Problem E. Doodle Jump</a></h3><h4>Brief description:</h4><p>You have been give <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>, <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>h</i></span> (gcd(<span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>) = 1), For each <span class=\"tex-span\"><i>ai</i></span> mod <span class=\"tex-span\"><i>p</i></span>, (<span class=\"tex-span\"><i>i</i></span>∈[1, n]), check weather the maximum distance in neighborhood after sorting is <= <span class=\"tex-span\"><i>h</i></span>. </p><h4>Analysis:</h4><p>Take <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 for example ... Divided the numbers in group.</p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 18\n</code></pre><p>We start a new group when the number > P</p><p>We found the difference between the elements of the first group is 5, The subsequent is filling some gap between the them ...</p><p>After some observation we could found that we should only consider into one gap ...(e.g. [0, 5] or [15, 20] or [20, 25] ... ) </p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>That says .. <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 is roughly equal to some things in small scale?</p><p>So let's check it in detail. Lemma 1. In any case, the gap after 20 won't better than any gap before it.</p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>For example, in this case, the gap after 20 is: 20, 22 And it has 16 in [15, 17] but no 21. </p><p>Is there any chance that [20, 23] is better than [15, 20]?</p><p>No, that is because, when there is no 21, then (19+5)%23 = 1, go to next floor. and there is no corresponding gap after 20 ([22, 24]) for this gap ([17, 19])</p><p>So we only need to consider [15, 20] ... and we found [15, 20] is roughly equal to [0, 5]</p> <pre><code>e.g. : 15 20 17 19 16 18 \nequal: 0 5 2 4 1 3\n</code></pre><p>we say 'roughly' because we havn't check some boundary case like there is 3 but on 18 ... </p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 \n</code></pre><p>If it happend, we should remove the number 3. .. If we can remove the element 5, then we can from a=5, p=23 to a'=2, p'=5 ...(n' = an/p, a' = a-p%a, if there is 3 but no 18, n'=n'-1)</p><p>The rest things is to discuss wheather 5 is necessary or not.</p><p>Let's we have:</p> <pre><code>0 2 4\n1 3\n</code></pre><p>If the 2*n'<5, then there is only one floor, the answer is max(2, 5-2*n'). If there is more than one floor, we could conclude that 5 is useless.</p><p>Proof: Elemets in 1st floor is: </p> <pre><code>0 a 2a 3a ...\n</code></pre><p>Let's say the maximum elements in 1st floor is x, then the minimum element in the 2nd floor is b0 = x+a-p, because b0 — a = x-p, so the difference between b0 and a is equal to the difference between x and p. That is, we can consider [b0, a] rather than [x, p], when there is a element insert in [b0, a], there must be some element insert in [x, p] in the same position.</p><p>So we have have succeeded to transform our original problem into a small one. Of couse, this problem havn't been solved, we haven't consider the time complexity. Says a' = a — p%a, when p = a+1, then a' = a-1, but we have <span class=\"tex-span\"><i>a</i></span> equal to 10^9, it won't work.</p><p>But, let's we have A1, A2, ... An ... and we subtract <span class=\"tex-span\"><i>d</i></span> from all of them, the answer won't be changed. So we can use p%a substitute for a-p%a, this is equivalent to we subtract %p% from all of them ...</p><p>So we set a' = min(a-p%a, p%a), so a'<=a/2, therefore, the final time complexity is <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span>.</p><p>You can check <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> <a href=\"//codeforces.com/contest/346/submission/4523388\">'s solution</a> for detail.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/346\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/347\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-4906-8958\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"4906\",\n blogEntryId: \"8903\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+56</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/MinakoKojima\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/MinakoKojima\">\n MinakoKojima\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8903#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8903#comments\">\n 66\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8974\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (56)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146290\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mohammadrdeh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/47/avatar/91eee3f7a5ec41f6.jpg'/> </a>\n <div><a href=\"/profile/mohammadrdeh\" title=\"Specialist mohammadrdeh\" class=\"rated-user user-cyan\">mohammadrdeh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146290\" href=\"?#comment-146290\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146290\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"14\"\r\n data-commentUserId=\"47\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+14</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146290\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>there is a typo: "... the classical <strong>LCA</strong> problem ..." => <strong>LCS</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146290 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146290 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146290\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146291\" commentParentId=\"146290\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146291\" href=\"?#comment-146291\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146290\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146291\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146291\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you. Fixed. m(_ _)m</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146291 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146291 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146291\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146297\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 05:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146297\" href=\"?#comment-146297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Actually our standard solution to C is O(b-a+n). O(b-a+n),O(b-a+nlogn),O((b-a+n)logn) are all able to pass during the test.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146297\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146335\" commentParentId=\"146297\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mmaxio\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/486/avatar/4bb53c24fc9e4c1.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/mmaxio\" title=\"International Master mmaxio\" class=\"rated-user user-orange\">mmaxio</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 17:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146335\" href=\"?#comment-146335\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146297\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146335\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146335\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"486\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146335\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>oh, never mind</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146335 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146335 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146335\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146299\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shashwat.gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6204/avatar/67f8e17c53f70578.jpg'/> </a>\n <div><a href=\"/profile/shashwat.gupta\" title=\"Specialist shashwat.gupta\" class=\"rated-user user-cyan\">shashwat.gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146299\" href=\"?#comment-146299\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146299\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"6204\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146299\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Problem B: Can you Explain little bit more on How "Aho-Corasick automation, or KMP" can help in figuring out smallest string that does not contain virus.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146299 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146299 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146299\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146300\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146300\" href=\"?#comment-146300\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146300\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146300\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For B, I already had the intuitive idea that this problem will be solved by either Aho-Corasick algorithm or KMP with dp, but I could not formalize the idea of states transition in dp. Could you please just provide the state in your dp algorithm?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146300 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146300 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146300\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146354\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146354\" href=\"?#comment-146354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146354\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Original problem can be solved by dp with two parameters DP[Len(s)] [Len(t)]. <a href=\"https://en.wikipedia.org/wiki/Longest_common_subsequence_problem\">http://en.wikipedia.org/wiki/Longest_common_subsequence_problem</a></p><p>To solve B you need to modificate it to DP[Len(s)][Len(t)][Len(virus)-1] where third parameter means maximum length of suffix of LCS that equal to prefix of virus.</p><p>To easy check where we go from K state (third parameter) by character C we can make automat on prefix function by virus.</p><p>Then if we stand in DP[i][j][k] :<br /> 1) if(s[i] == t[j] and Automat[k][c]<Len(virus) we try to relax DP[i+1][j+1][Automat[k][c]]<br /> 2) Try to relax DP[i][j+1][k] and DP[i+1][j][k]</p><p><strong>UPD</strong> My solution: <a href=\"//codeforces.com/contest/346/submission/4532899\">http://codeforces.com/contest/346/submission/4532899</a> (hope it understandable)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146354\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146357\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146357\" href=\"?#comment-146357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>got it, many thanks to you man :) Also understood why KMP tag mentioned in the problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146357\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146493\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lama\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/72190/avatar/735906a91d1576e3.jpg'/> </a>\n <div><a href=\"/profile/lama\" title=\"Expert lama\" class=\"rated-user user-blue\">lama</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 18:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146493\" href=\"?#comment-146493\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146493\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146493\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) Can you please explain what "maximum length of suffix of LCS that equal to prefix of virus" means? 2) What is an automat?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146493 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146493 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146493\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146519\" commentParentId=\"146493\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/25/2013 05:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146519\" href=\"?#comment-146519\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146493\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146519\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146519\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146519\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) We stand in DP[i][j][k]-state (in which we store longest LCS), virus = "virus" <br /> Let's go from k = 0 to 4,then:</p> <pre><code>0) DP[i][j][0] means that finded LCS not ends on "v" or "vi" or "vir" or "viru" or "virus". (example: "a")\n\n1) DP[i][j][1] means that finded LCS ends on "v", but not on "vi" or "vir" or "viru" or "virus". (example: "av")\n\n2) DP[i][j][2] means that finded LCS ends on "vi", but not on "vir" or "viru" or "virus". (example: "avi")\t\n\n3) DP[i][j][3] means that finded LCS ends on "vir", but not on "viru" or "virus". (example: "avir")\n\n4) DP[i][j][4] means that finded LCS ends on "viru", but not on "virus". (example: "aviru")\n\nWe take "longest suffix of LCS that equal prefix of virus", because virus could be: "vvvvv" or "ababv" (and infinite others)\n If LCS = "avvv" - it ends on "v","vv","vvv". (virus = "vvvvv")\n If LCS = "aabab" - it ends on "ab" and "abab". (virus = "ababv")\n</code></pre><p><a href=\"https://en.wikipedia.org/wiki/Knuth%E2%80%93Morris%E2%80%93Pratt_algorithm\">KMP</a></p><p>2) <a href=\"https://en.wikipedia.org/wiki/Automata_theory\">http://en.wikipedia.org/wiki/Automata_theory</a></p><p>Can't find nothing about automaton on prefix-function in english. I hope you will be able understand <a href=\"http://e-maxx.ru/algo/prefix_function\">this</a> with some translator (google translate for example).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146519 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146519 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146519\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"551712\" commentParentId=\"146519\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/srv_twry\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/447741/avatar/d1a80b00eb029c2b.jpg'/> </a>\n <div><a href=\"/profile/srv_twry\" title=\"Expert srv_twry\" class=\"rated-user user-blue\">srv_twry</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/19/2019 12:58\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-551712\" href=\"?#comment-551712\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146519\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"551712\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"447741\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-551712\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Fortunately, the e-maxx article on Prefix function has been translated in English and can be found here: <a href=\"https://cp-algorithms.com/string/prefix-function.html#toc-tgt-12\">prefix-function: automaton on prefix-function</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-551712 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-551712 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-551712\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"768401\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ttbbnnn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1694563/avatar/ff85df0301cf6f76.jpg'/> </a>\n <div><a href=\"/profile/ttbbnnn\" title=\"Master ttbbnnn\" class=\"rated-user user-orange\">ttbbnnn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2021 20:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-768401\" href=\"?#comment-768401\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"768401\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1694563\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-768401\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My solution for B got a WA on test 41 and I don't know why :<, please help me with this code: <a href=\"https://codeforces.com/contest/346/submission/109283664\">https://codeforces.com/contest/346/submission/109283664</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-768401 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-768401 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-768401\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146301\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146301\" href=\"?#comment-146301\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146301\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146301\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146301\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"So the remians work is to delete those same xi, and watch out some situation could cause degeneration. Many of us failed in this last step and got TLE", I really could not understand this. What you you mean by degeneration in this case? Please explain this last important step.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146301 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146301 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146301\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146302\" commentParentId=\"146301\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:37\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146302\" href=\"?#comment-146302\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146301\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146302\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146302\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>suppose b=1, all x[i]>a, what will happen?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146302 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146302 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146302\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146304\" commentParentId=\"146302\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146304\" href=\"?#comment-146304\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146302\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146304\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146304\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As b = 1, All x[i] > a. Then a % x[i] = a. So if we take this, then we will lead to a — a = 0, which is less than b. So we need to move one by one, so answer would be a.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146304 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146304 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146304\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146309\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146309\" href=\"?#comment-146309\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146309\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146309\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Alice and Bob problem how do you prove that you will always get {d, 2d, 3d, ... max{xi}} in the end. It is easy to see but I am unable to prove it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146309 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146309 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146309\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146365\" commentParentId=\"146309\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marat.snowbear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98082/avatar/1499cf6d0c86172.jpg'/> </a>\n <div><a href=\"/profile/marat.snowbear\" title=\"International Master marat.snowbear\" class=\"rated-user user-orange\">marat.snowbear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146365\" href=\"?#comment-146365\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146309\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146365\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"98082\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146365\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I convinced myself like this:</p> <ol> <li>Prove that we will be able to get d by some sequence of subtractions.</li> <li>Prove that we will be able to generate {d, 2d, 3d, ...}</li> <li>Prove that we will not be able to get anything else except for { d, 2d, 3d, ... }</li> </ol><p>In details:</p> <ol> <li><p>See <a href=\"https://en.wikipedia.org/wiki/Euclidean_algorithm\">Euclidean algorithm for finding GCD</a>. If you will look into the description or code you will see that it does exactly what is asked in this problem — subtracts numbers one from another. And the result is GCD of original two numbers. So you can see that by some sequence of subtractions you can get GCD.</p></li> <li><p>If you already have d which GCD of all the numbers then you can easily fill all the gaps in { d, 2d, 3d, ..., max } sequence by starting subtracting d from { max, max — d, max — 2d, ... }. So you will get the intended set.</p></li> <li><p>You cannot subtract two numbers a and b which have GCD(a, b) = d and get result which won't be dividable by d. So if you start with set where every numbers can be divided by d then no matter what you subtract you will always have the result which is also dividable by d.</p></li> </ol></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146365 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146365 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146365\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146390\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 16:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146390\" href=\"?#comment-146390\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146390\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146390\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, got it. Thanks!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146390 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146390 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146390\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"774539\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/25/2021 20:24\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-774539\" href=\"?#comment-774539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"774539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-774539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-774539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-774539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-774539\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146310\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i_coder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i_coder\" title=\"Expert i_coder\" class=\"rated-user user-blue\">i_coder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146310\" href=\"?#comment-146310\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146310\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"41979\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146310\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Is this the final editorial (except the D problem) ? The explanations to problems B and C are very limited and not at all well elaborated.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146310 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146310 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146310\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146314\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146314\" href=\"?#comment-146314\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146314\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146314\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can you tell me that why the number of rounds in Problem A will be max(xi)/d-n ? How do you come to this point ? can you please tell me this as am not to figure out this thing ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146314 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146314 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146314\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146316\" commentParentId=\"146314\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:45\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146316\" href=\"?#comment-146316\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146314\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146316\" revisionCount=\"7\" revision=\"7\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">7</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146316\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146316\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>take example <br /> 3 9 54 <br /> gcd (3, 9, 54) = 3 <br /> Now total rounds possible including (3, 9, 54) =<br />all multiples of 3 upto 54 <br /> 3, 6, 9, 12, 15, 18 ... 54 <br /> </p><p>So total count of these numbers = 54 / 3 = 18. <br /> </p><p>Now as out of these numbers 3 numbers are already taken, so subtract 3 <br /> so rounds remaining = 18 — 3 = 15 </p><p>Now it is very easy to generalize for 3 being d and 54 being n</p><p>answer would be n / d — n. <br /> I hope it is clear now :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146316 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146316 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146316\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146319\" commentParentId=\"146316\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146319\" href=\"?#comment-146319\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146316\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146319\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146319\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes, it is more clear to me now. but one thing is that how did you approach to gcd thing ? I understood the problem, the logic and all. how did you approach that it will be done using gcd thing and all ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146319 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146319 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146319\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146322\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146322\" href=\"?#comment-146322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146322\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My Ideas during solving the problem: <br /> all the examples had gcd 1. So I directly thought answer as max(xi) — n. <br /> But I thought it can not be too simple, I need to think more. <br /> So I took a case 2 4 6, I immediately found I am wrong in this case. <br /> Then the idea came into mind that if gcd of numbers is g. then we can not create any number not divisible by g because (g *k1 — k * k2) = g * (k1 — k2). </p><p>So Finally I coded it and got accpeted :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146322\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146338\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 19:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146338\" href=\"?#comment-146338\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146338\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146338\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>given the numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>, what is the minimum positive value you can achieve by combining them? </p><p>Let's write down the equation: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>·<i>x</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub>·<i>x</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>n</i></sub>·<i>x</i><sub class=\"lower-index\"><i>n</i></sub> = <i>d</i></span>, where <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> are some unknown integers. </p><p>It is, as you can see, none other than linear Diophantine equation. And it is known there is no solutions if <span class=\"tex-span\"><i>d</i></span> is not a multiple of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span> </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146338 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146338 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146338\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146317\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/subway\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123924/avatar/706e86f587cbabf0.jpg'/> </a>\n <div><a href=\"/profile/subway\" title=\"Expert subway\" class=\"rated-user user-blue\">subway</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146317\" href=\"?#comment-146317\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146317\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146317\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@hellodear-the final set will contain all elements {d,2d,3d,..max(Xi)} (d=gcd of all elements) so total no. of elements in final set =max(Xi)/d since initially we have 'n' elements total no. of new elements to be added in set to make it complete=(max(Xi)/d)-n.. hope this helps you..:)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146317 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146317 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146317\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146320\" commentParentId=\"146317\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146320\" href=\"?#comment-146320\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146317\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146320\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146320\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in this thing, I was applying some game theory, but it doesn't include anything like that. when the question says optimally, then how do you form examples so as to test your code on them ? because optimally means in the best they can. can you elaborate ? thanks to you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146320 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146320 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146320\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146324\" commentParentId=\"146320\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146324\" href=\"?#comment-146324\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146320\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146324\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146324\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146324\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>optimality argument is simple and also given in the editorial itself. <br /> As total you numbers finally would be {d, 2 * d,, .,, max (xi)}. <br /> Hence whatever you add to the these set, no other person will be able to add that as he has to add a new number everytime to this test. <br /> So outcome depend on the parity of turns.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146324 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146324 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146324\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146325\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sinamosavi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/87557/avatar/bde58fa97bcc5eb0.jpg'/> </a>\n <div><a href=\"/profile/sinamosavi\" title=\"Pupil sinamosavi\" class=\"rated-user user-green\">sinamosavi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146325\" href=\"?#comment-146325\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146325\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"87557\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146325\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the complete proof for A.Div1 is not that much straightforward. Maybe I'm making it too much difficult, but this is my complete proof:</p><p>First by induction, we prove that the numbers in the end will be <span class=\"tex-span\"><i>a</i>, 2<i>a</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Let <span class=\"tex-span\"><i>g</i> = <i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ... , <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span>. It's trivial that in the end <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>. Assume that <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>, because our numbers will be <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), 2<i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>, so we would have a new gcd. That's a contradiction, so <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) = <i>g</i></span> and our numbers will be <span class=\"tex-span\"><i>g</i>, 2<i>g</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Each move adds one number and in the end there will be <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e6ac12549498d8aaad3d63270d12497bc74a9f84.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> numbers, so the answer wil be the parity of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/48ba1bfd0fa315ab1595947b8e046b4cc211b908.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Sorry for my bad English.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146325 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146325 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146325\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146332\" commentParentId=\"146325\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146332\" href=\"?#comment-146332\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146325\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146332\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-13\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146332\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What about this test <code>2 3 5</code>? <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≠ <i>gcd</i></span></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146332 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146332 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146332\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146333\" commentParentId=\"146332\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146333\" href=\"?#comment-146333\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146332\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146333\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146333\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Oops. You've meant that <span class=\"tex-span\"><i>a</i></span> — is the result. Sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146333 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146333 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146333\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146334\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 16:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146334\" href=\"?#comment-146334\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146334\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146334\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146334\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>But how to prove that there is always a way to choose <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> while the number of the current round less than the maximum number of rounds? (Div2C)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146334 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146334 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146334\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146339\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:22\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146339\" href=\"?#comment-146339\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146339\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146339\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146339\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If gcd{xi}＝1, then for every xi there must exist ti to make sum｛xi*ti｝＝1. </p><p>(For example, x1＝5,x2＝7,then t1＝3,t2＝-2.x1*t1＋x2*t2＝1.)</p><p>And sum{xi*ti} can be performed in a few turns. ( (5-(7-5))-(7-5). )</p><p>And if we can get 1, then what number between [1,max{xi}] can't we get？</p><p>if gcd{xi}≠1.the proof is similar.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146339 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146339 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146339\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146341\" commentParentId=\"146339\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146341\" href=\"?#comment-146341\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146339\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146341\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146341\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why there is must exist such t[i]?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146341 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146341 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146341\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146366\" commentParentId=\"146341\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146366\" href=\"?#comment-146366\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146341\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146366\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146366\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You must know if gcd(a,b)＝1, there must exist x and y to make ax＋by＝1. It can be proved from this.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146366 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146366 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146366\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146376\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146376\" href=\"?#comment-146376\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146376\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146376\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146376\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So.. If we divide all the numbers by GCD, and after that a pair of coprime numbers have appeared, we always can reach 1. Let's choose coprime <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, then <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> will be also coprime with <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, and it will be less then <span class=\"tex-span\"><i>max</i>(<i>x</i>, <i>y</i>)</span>. So we can choose <span class=\"tex-span\"><i>mid</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>x</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>min</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>y</i><sub class=\"lower-index\">1</sub></span>, and they are coprime, and <span class=\"tex-span\">|<i>x</i><sub class=\"lower-index\">1</sub> - <i>y</i><sub class=\"lower-index\">1</sub>|</span> will be less than <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>. And etc. by induction. But what to do if there is not a pair of coprime numbers after dividing by GCD? For example <code>35 45 63</code>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146376 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146376 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146376\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146404\" commentParentId=\"146376\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146404\" href=\"?#comment-146404\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146376\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146404\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146404\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146404\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>63*2＋45*5＋35*(-10)＝1</p><p>Because gcd (35,45)＝5, we can consider 35 and 45 as one number 5x. Because gcd(5,63)＝1, so there must exist x,y to make 5x＋63y＝1.</p><p>So here comes a tragedy. We can get 5 first. Then we use this number together with 63 to make 1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146404 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146404 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146404\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146346\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KiAsaGibona\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/KiAsaGibona\" title=\"Specialist KiAsaGibona\" class=\"rated-user user-cyan\">KiAsaGibona</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 21:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146346\" href=\"?#comment-146346\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146346\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146346\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"99053\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146346\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Someone please explain the greedy idea of (Div 1 C) (Number Transformation II). Thanks in advance :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146346 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146346 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146346\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146367\" commentParentId=\"146346\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 09:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146367\" href=\"?#comment-146367\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146346\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146367\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146367\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's a pretty simple greedy idea: Just pick the <code>x</code> that makes the value of <code>a</code> smallest after applying the operation <code>a = a - a%x</code> (or subtract 1 if no choice for <code>x</code> makes <code>a</code> smaller). The proof why this works is given in the editorial: it is never better to get a larger number, so you should get the smallest one you can.</p><p>As listed on the last paragraph of the editorial you have to be careful to remove all <code>x</code> that are either duplicates or cannot be used anymore (<code>a - (a%x)</code> is smaller than <code>b</code>), otherwise you will get TLE.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146367 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146367 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146367\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146382\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146382\" href=\"?#comment-146382\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146382\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146382\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146382\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>how to find this x for each number?</p><p>we will iterate on all x[i]s and only delete x[i]s when x[i] > a?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146382 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146382 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146382\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146405\" commentParentId=\"146382\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146405\" href=\"?#comment-146405\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146382\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146405\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146405\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Iterate through all x[i]s and delete them when a — (a%x[i]) is smaller than b (if you only delete when x[i] > a, you will also get TLE).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146405 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146405 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146405\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146625\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 17:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146625\" href=\"?#comment-146625\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146625\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146625\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm really striving to understand why the algorithm turns out to be linear instead of quadratic... I know the editorial says "That is because, we could cut exactly <span class=\"tex-span\"><i>max</i>{<i>xi</i>}</span> in each 2 step.", but I can't really get what it means :\\</p><p>Can you give me a hint? Thanks :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146625 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146625 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146625\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146643\" commentParentId=\"146625\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/xenoslash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88090/avatar/f75f8cbc20d6133f.jpg'/> </a>\n <div><a href=\"/profile/xenoslash\" title=\"Expert xenoslash\" class=\"rated-user user-blue\">xenoslash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 19:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146643\" href=\"?#comment-146643\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146625\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146643\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146643\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"88090\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146643\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have an easy intuition of cutting at least max{xi} in O(1) steps, not sure what was the intended 2 step proofs though. I am going to use xi to refer to max{xi}, and assume that proper care is taken to only keep the relevant xi's.</p><p>When we do a-(a % xi), we bring caused a to be the next largest integer <= a that is a multiple of xi, since now new_a % xi = 0. Then, if a is divisible by xi, you can do.., do a-1 (causing it to be non-divisible by xi), then finally a-(a%xi) again. In this 3 step sequence you have brought a down to the next lower multiple of xi, and have essentially cut max{xi} in O(1) number of steps.</p><p>Sample code : <a href=\"//codeforces.com/contest/346/submission/4545367\">http://codeforces.com/contest/346/submission/4545367</a> Yeah I used tree set so it's not exactly O(n).. but hash set keeps giving me TLE :(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146643 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146643 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146643\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146689\" commentParentId=\"146643\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2013 12:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146689\" href=\"?#comment-146689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146643\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you very much, that was really eye-opening! This is why I love Codeforces, great community! :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146689\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146371\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Corvo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/11909/avatar/8404ac1aff5270ec.jpg'/> </a>\n <div><a href=\"/profile/Corvo\" title=\"Pupil Corvo\" class=\"rated-user user-green\">Corvo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 12:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146371\" href=\"?#comment-146371\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146371\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"11909\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146371\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please explain why the problem is solved through the GDC (A)? I tried like <a href=\"https://codeforces.com/contest/347/submission/4535232\">this</a>, but I still can not understand why you can not do. Please give a short test on which the decision falls. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146371 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146371 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146371\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146375\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146375\" href=\"?#comment-146375\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146375\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146375\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><pre><code>3\n14 4 2\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146375 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146375 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146375\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146378\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akashdeep\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/39866/avatar/6f66d1bbe26ef4ca.jpg'/> </a>\n <div><a href=\"/profile/akashdeep\" title=\"International Master akashdeep\" class=\"rated-user user-orange\">akashdeep</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146378\" href=\"?#comment-146378\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146378\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"39866\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146378\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Because only those numbers are possible in the game which are multiple of gcd. See this simplest test case</p> <pre><code>2\n4 6\n</code></pre><p>The only number possible in the game is (6-4) i.e. 2, but in your code u are assuming that somehow these (1,2,3,5) numbers can be obtained which is a wrong assumption.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146378 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146378 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146378\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146408\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/NegaTeeF\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/NegaTeeF\" title=\"Master NegaTeeF\" class=\"rated-user user-orange\">NegaTeeF</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 20:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146408\" href=\"?#comment-146408\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146408\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"65829\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146408\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Explain please, how to do Div1-D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146408 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146408 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146408\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146410\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/irakli_p\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29034/avatar/d879a3156498c6c7.jpg'/> </a>\n <div><a href=\"/profile/irakli_p\" title=\"Expert irakli_p\" class=\"rated-user user-blue\">irakli_p</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 21:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146410\" href=\"?#comment-146410\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146410\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29034\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146410\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i didn't understand Div 2 — D can someone explain it to me please </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146410 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146410 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146410\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146443\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/suiyuan2009\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49923/avatar/9065a92c0b30b883.jpg'/> </a>\n <div><a href=\"/profile/suiyuan2009\" title=\"Master suiyuan2009\" class=\"rated-user user-orange\">suiyuan2009</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 13:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146443\" href=\"?#comment-146443\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146443\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49923\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146443\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>problem B,ac automachine is doing the thing that belong to kmp</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146443 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146443 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146443\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146452\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 17:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146452\" href=\"?#comment-146452\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146452\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146452\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div1_E: Should the "Doodler" jump over the platform which H = P ? I just confused about that.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146452 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146452 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146452\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146480\" commentParentId=\"146452\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 11:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146480\" href=\"?#comment-146480\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146452\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146480\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146480\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OK I got the answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146480 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146480 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146480\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146463\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146463\" href=\"?#comment-146463\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146463\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"44\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+44</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146463\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>still waiting for D tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146463 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146463 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146463\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147566\" commentParentId=\"146463\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/05/2013 05:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147566\" href=\"?#comment-147566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146463\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>.. Update .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147566\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"235917\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/saurabhverma\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/143428/avatar/48808a8d5db775d4.jpg'/> </a>\n <div><a href=\"/profile/saurabhverma\" title=\"Expert saurabhverma\" class=\"rated-user user-blue\">saurabhverma</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2015 20:05\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-235917\" href=\"?#comment-235917\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"235917\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"143428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-235917\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In my approach to problem div1 B, I calculated longest common subsequence, prepended virus to it, calculated the Z function and deleted every character which had z[i] >= virus.size(). I don't think my approach is wrong. Can someone tell me if my code is wrong or the approach has some flaw. Thanks. Submission : <a href=\"//codeforces.com/contest/346/submission/11491420\">http://codeforces.com/contest/346/submission/11491420</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-235917 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-235917 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-235917\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"530287\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arpit4427\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/717924/avatar/90dcbc94a1e57cf.jpg'/> </a>\n <div><a href=\"/profile/arpit4427\" title=\"Expert arpit4427\" class=\"rated-user user-blue\">arpit4427</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/26/2019 14:04\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-530287\" href=\"?#comment-530287\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"530287\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"530287\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"717924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-530287\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone explain how to solve this problem <a href=\"/contest/346/problem/B\" title=\"Codeforces Round 201 (Div. 1)\">346B - Lucky Common Subsequence</a>? I have went thorugh the editorial but I could not understand.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-530287 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-530287 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-530287\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8974\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8974 = true;\r\nvar lastPreviewContent8974 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8974] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8974] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:24</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812874998e81759f',t:'MTY5NjcwNTk0NS4wMjkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1750,"cells":{"problem_id":{"kind":"string","value":"346D"},"contest":{"kind":"string","value":"346"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Robot Control"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Robot Control</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>6 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>The boss of the Company of Robot is a cruel man. His motto is \"Move forward Or Die!\". And that is exactly what his company's product do. Look at the behavior of the company's robot when it is walking in the directed graph. This behavior has been called \"Three Laws of Robotics\":</p><ul> <li> Law 1. The Robot will destroy itself when it visits a vertex of the graph which it has already visited. </li><li> Law 2. The Robot will destroy itself when it has no way to go (that is when it reaches a vertex whose out-degree is zero). </li><li> Law 3. The Robot will move randomly when it has multiple ways to move (that is when it reach a vertex whose out-degree is more than one). Of course, the robot can move only along the directed edges of the graph. </li></ul><p>Can you imagine a robot behaving like that? That's why they are sold at a very low price, just for those who are short of money, including mzry1992, of course. mzry1992 has such a robot, and she wants to move it from vertex <span class=\"tex-span\"><i>s</i></span> to vertex <span class=\"tex-span\"><i>t</i></span> in a directed graph safely without self-destruction. Luckily, she can send her robot special orders at each vertex. A special order shows the robot which way to move, if it has multiple ways to move (to prevent random moving of the robot according to Law 3). When the robot reaches vertex <span class=\"tex-span\"><i>t</i></span>, mzry1992 takes it off the graph immediately. So you can see that, as long as there exists a path from <span class=\"tex-span\"><i>s</i></span> to <span class=\"tex-span\"><i>t</i></span>, she can always find a way to reach the goal (whatever the vertex <span class=\"tex-span\"><i>t</i></span> has the outdegree of zero or not). </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/c884535eed73951c30ddcfe872a1588183e0d72a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> Sample 2 </center><p>However, sending orders is expensive, so your task is to find the minimum number of orders mzry1992 needs to send in the worst case. Please note that mzry1992 can give orders to the robot <span class=\"tex-font-style-bf\">while it is walking</span> on the graph. Look at the first sample to clarify that part of the problem.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">6</sup></span>) — the number of vertices of the graph, and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">6</sup></span>) — the number of edges. Then <span class=\"tex-span\"><i>m</i></span> lines follow, each with two integers <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>u</i><sub class=\"lower-index\"><i>i</i></sub>, <i>v</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>; <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>u</i><sub class=\"lower-index\"><i>i</i></sub></span>), these integers denote that there is a directed edge from vertex <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub></span> to vertex <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span>. The last line contains two integers <span class=\"tex-span\"><i>s</i></span> and <span class=\"tex-span\"><i>t</i></span> (<span class=\"tex-span\">1 ≤ <i>s</i>, <i>t</i> ≤ <i>n</i></span>).</p><p>It is guaranteed that there are no multiple edges and self-loops.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If there is a way to reach a goal, print the required minimum number of orders in the worst case. Otherwise, print -1.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4 6<br/>1 2<br/>2 1<br/>1 3<br/>3 1<br/>2 4<br/>3 4<br/>1 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 5<br/>1 2<br/>2 1<br/>1 3<br/>2 4<br/>3 4<br/>1 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first test sample. Initially the robot is on vertex 1. So, on the first step the robot can go to vertex 2 or 3. No matter what vertex the robot chooses, mzry1992 must give an order to the robot. This order is to go to vertex 4. If mzry1992 doesn't give an order to the robot at vertex 2 or 3, the robot can choose the \"bad\" outgoing edge (return to vertex 1) according Law 3. So, the answer is one.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"41ebe9b6ad5457d7f748c134821c49dc\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"76ca6f0bbc2c68c0c469d82a1a1c06e9e639f443\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='41ebe9b6ad5457d7f748c134821c49dc'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F346%2Fproblem%2FD%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='41ebe9b6ad5457d7f748c134821c49dc'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/346\">Codeforces Round 201 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='41ebe9b6ad5457d7f748c134821c49dc'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/346/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Graphs\">\r\n graphs\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Shortest paths on weighted and unweighted graphs\">\r\n shortest paths\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2600\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='41ebe9b6ad5457d7f748c134821c49dc'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3506\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='41ebe9b6ad5457d7f748c134821c49dc'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3506\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8896\" title=\"Codeforces Round #201\" target=\"_blank\">Codeforces Round #201</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1860:1861\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8903\" title=\"Codeforces Round #201 Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1864\" resourceName=\"Codeforces Round #201 Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/346\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/346/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/346/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/346/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/346/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/346/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/346/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/346/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_ad87097d2bfd2bfe24b963d0414661d8a2cc6fff\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Robot Control</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>6 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>The boss of the Company of Robot is a cruel man. His motto is "Move forward Or Die!". And that is exactly what his company's product do. Look at the behavior of the company's robot when it is walking in the directed graph. This behavior has been called "Three Laws of Robotics":</p><ul> <li> Law 1. The Robot will destroy itself when it visits a vertex of the graph which it has already visited. </li><li> Law 2. The Robot will destroy itself when it has no way to go (that is when it reaches a vertex whose out-degree is zero). </li><li> Law 3. The Robot will move randomly when it has multiple ways to move (that is when it reach a vertex whose out-degree is more than one). Of course, the robot can move only along the directed edges of the graph. </li></ul><p>Can you imagine a robot behaving like that? That's why they are sold at a very low price, just for those who are short of money, including mzry1992, of course. mzry1992 has such a robot, and she wants to move it from vertex <span class=\"tex-span\"><i>s</i></span> to vertex <span class=\"tex-span\"><i>t</i></span> in a directed graph safely without self-destruction. Luckily, she can send her robot special orders at each vertex. A special order shows the robot which way to move, if it has multiple ways to move (to prevent random moving of the robot according to Law 3). When the robot reaches vertex <span class=\"tex-span\"><i>t</i></span>, mzry1992 takes it off the graph immediately. So you can see that, as long as there exists a path from <span class=\"tex-span\"><i>s</i></span> to <span class=\"tex-span\"><i>t</i></span>, she can always find a way to reach the goal (whatever the vertex <span class=\"tex-span\"><i>t</i></span> has the outdegree of zero or not). </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/c884535eed73951c30ddcfe872a1588183e0d72a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> Sample 2 </center><p>However, sending orders is expensive, so your task is to find the minimum number of orders mzry1992 needs to send in the worst case. Please note that mzry1992 can give orders to the robot <span class=\"tex-font-style-bf\">while it is walking</span> on the graph. Look at the first sample to clarify that part of the problem.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">6</sup></span>) — the number of vertices of the graph, and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">6</sup></span>) — the number of edges. Then <span class=\"tex-span\"><i>m</i></span> lines follow, each with two integers <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>u</i><sub class=\"lower-index\"><i>i</i></sub>, <i>v</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>; <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>u</i><sub class=\"lower-index\"><i>i</i></sub></span>), these integers denote that there is a directed edge from vertex <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub></span> to vertex <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span>. The last line contains two integers <span class=\"tex-span\"><i>s</i></span> and <span class=\"tex-span\"><i>t</i></span> (<span class=\"tex-span\">1 ≤ <i>s</i>, <i>t</i> ≤ <i>n</i></span>).</p><p>It is guaranteed that there are no multiple edges and self-loops.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If there is a way to reach a goal, print the required minimum number of orders in the worst case. Otherwise, print -1.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4 6<br />1 2<br />2 1<br />1 3<br />3 1<br />2 4<br />3 4<br />1 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 5<br />1 2<br />2 1<br />1 3<br />2 4<br />3 4<br />1 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first test sample. Initially the robot is on vertex 1. So, on the first step the robot can go to vertex 2 or 3. No matter what vertex the robot chooses, mzry1992 must give an order to the robot. This order is to go to vertex 4. If mzry1992 doesn't give an order to the robot at vertex 2 or 3, the robot can choose the "bad" outgoing edge (return to vertex 1) according Law 3. So, the answer is one.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:50</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bddbad417593',t:'MTY5NjY0NjAzMC43NjcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Dynamic programming\", \"Graphs\", \"Shortest paths on weighted and unweighted graphs\"]"},"short_tags":{"kind":"string","value":"[\"dp\", \"graphs\", \"shortest paths\", \"*2600\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8903"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"1c88316eb9ff5851524d80ea59ef3f32\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #201 Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #201 Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='1c88316eb9ff5851524d80ea59ef3f32'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8903\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/MinakoKojima\">MinakoKojima</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/MinakoKojima\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/MinakoKojima\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/MinakoKojima\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/MinakoKojima\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/MinakoKojima\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/MinakoKojima\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/MinakoKojima\" style=\"text-decoration:none;color:black !important;\">MinakoKojima's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8958\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8903\"> <p>Codeforces Round #201 Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a>,\r\n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><img alt=\" \" src=\"/predownloaded/41/3f/413f7303374a112dddc1e63e29cfc12924514cd7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><h1>Overview</h1><p>In DIV 1, there are 4 interesting problems together with a normal one. We think it is reasonable because we can't have a round fullly with intelligence. Problem A, C have weak pretests while others intended to be strong. About more then 200 participants solve A in the early 45mins, then a few of them start from C while most of the other start from B. </p><p>Problem B is a rather standard problem, but if you're unfamiliar with the algorithm, it can be very hard. Problem C is a more intersting problem. As the name implies, there was <a href=\"//codeforces.com/problemset/problem/251/C\">a similar version</a> in the previous round before, but this time it has a brand new constrains.(So here we have a psychology experiment: could different constrains make people thinking in a slightly different way?ww)</p><p>The standard solution of problem C is <span class=\"tex-span\"><i>O</i>((<i>b</i> - <i>a</i>) + <i>nlogn</i>)</span>. The first expected correct solution was written by <a class=\"rated-user user-orange\" href=\"/profile/zeliboba\" title=\"International Master zeliboba\">zeliboba</a>. <a href=\"//codeforces.com/contest/346/submission/4512654\">http://codeforces.com/contest/346/submission/4512654</a></p><p>After that, some people start to solve problem D. Problem D looks like a hard dp problem on a graph at the first glance, the key point is how to avoid the circle in the transfer equation. It turn out to be elegant after you could found a right order of the evaluation. Problem E is challenging which you need find a way to transform the original question into a smaller scale, and cut off many many corner cases ... And in the very end, you find a way like binary search to get <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span> as the time complexity. No one manage to solve problem E during the contest, maybe <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> is the man who closest to it.</p><p>The winner comes to <a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"Grandmaster cgy4ever\">cgy4ever</a>, because he found the draw-black in his previous C submission during the very beginning even when there is nobody hack him! He resubmit it decisively and get back when finished problem D. After that, he use the same trick which made him failed before to hack others and got a handsomely rewards. The second place went to <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a>, because of the combination of decent speed in A, B, C, D.</p><p>Problem B belongs to me, problem C belongs to <a class=\"rated-user user-violet\" href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\">CMHJT</a> and others belong to <a class=\"rated-user user-orange\" href=\"/profile/UESTC_Nocturne\" title=\"International Master UESTC_Nocturne\">UESTC_Nocturne</a>. The illustrator of problem C is <a href=\"http://www.pixiv.net/member_illust.php?mode=medium&illust_id=38602657\">Chairman Miao(貓主席)</a>.</p><h1>Editorial</h1><h3><a href=\"//codeforces.com/problemset/problem/346/A\">Problem A. Alice and Bob</a></h3><h4>Brief description:</h4><p>Alice and Bob play a game, the rules are as follows: First, they will get a set of <span class=\"tex-span\"><i>n</i></span> distinct numbers. And then they take turns to do the following operations. During each operation, either Alice or Bob can choose two different numbers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> from the set, as long as <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> is not in the set, then they add it to the set. The person who can not choose two numbers successfully will lose the game. The question is who will finally win the game if both of them do operations optimally. Remember that Alice always goes first.</p><h4>Analysis:</h4><p>First, no matter what happend, the number set we get at the very endding will be same all the time. Let's say <span class=\"tex-span\"><i>d</i> = <i>gcd</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}. Then the set in the endding will be some things like {<span class=\"tex-span\"><i>d</i></span>, <span class=\"tex-span\">2<i>d</i></span>, <span class=\"tex-span\">3<i>d</i></span>, ... <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}}. So there is always <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub>} / <i>d</i></span> — <span class=\"tex-span\"><i>n</i></span> rounds. And what we should do rest is to check the parity of this value.</p><h3><a href=\"//codeforces.com/problemset/problem/346/B\">Problem B. Lucky Common Subsequence</a></h3><h4>Brief description:</h4><p>You have been given two strings <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and <span class=\"tex-span\"><i>virus</i></span>, and you have to find the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> without <span class=\"tex-span\"><i>virus</i></span> as a substring.</p><h4>Analysis:</h4><p>This is a rather classical problem, let's say if there is no virus, then it is the classical **LCS ** problem. You can solve this by a <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> dynamic programing.</p><p>When consider about the virus, we should add 1 more dimension on the state to trace the growth of the virus. It can be done by wheather <strong>Aho-Corasick automation</strong>, or <strong>KMP</strong> when there is only one virus in this case. The overall time complexity is <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">3</sup>)</span>.</p><h3><a href=\"//codeforces.com/problemset/problem/346/C\">Problem C. Number Transformation II</a></h3><h4>Brief description:</h4><p>You have a number <span class=\"tex-span\"><i>b</i></span>, and want to minus it to <span class=\"tex-span\"><i>a</i></span>, what you can do in each step is weather subtract 1 or <span class=\"tex-span\"><i>b</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> from <span class=\"tex-span\"><i>b</i></span>. And we ask what is the minimum number of steps you need.</p><h4>Analysis:</h4><p>I bet there is a few people know the greedy method even if he/she have solved the early version before.</p><p><a href=\"//codeforces.com/problemset/problem/251/C\">Codeforces #153 Div 1. Problem C. Number Transformation</a></p><p>Let dp[k] denotes the minimum number of steps to transform b+k to b. In each step, you could only choose i which makes b+k-(b+k) mod x[i] minimal to calc dp[k]. It works bacause dp[0..k-1] is a monotone increasing function. Proof: - Say dp[k]=dp[k-t]+1.If t==1, then dp[0..k] is monotone increasing obviously.Otherwise dp[k-1]<=dp[k-t]+1=dp[k] (there must exist a x[i] makes b+k-1 also transform to b+k-t,and it is not necessarily the optimal decision of dp[k-1]). So dp[k] is a monotone increasing function, we can greedily calc dp[a-b].</p><p>In the first glance, it looks like something which will run in square complexity. But actually is linear. That is because, we could cut exactly max{<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>} in each 2 step. It can be proof by induction.</p><p>So the remians work is to delete those same <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>, and watch out some situation could cause degeneration. Many of us failed in this last step and got <strong>TLE</strong></p><h3><a href=\"//codeforces.com/problemset/problem/346/D\">Problem D. Robot Control</a></h3><p>Let's dp from t to s.</p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>Here dp[u] means, the minimum number of orders mzry1992 needs to send in the worst case. The left-hand-side is sending order while the right-hand side is not. At the beginning, we have dp[t] = 1, and dp[s] will be the answer.</p><p>We can see there is circular dependence in this equation, in this situation, one standard method is using Bellman-Ford algorithm to evaluate the dp function.</p><p>But it is not appropriate for this problem.</p><p>(In fact, we add a part of targeted datas in pretest, these datas are enough to block most of our <a href=\"https://en.wikipedia.org/wiki/Bellman%E2%80%93Ford_algorithm\">Bellman-Ford algorithm</a>, although there is still a few participator can get accepted by Bellman-Ford algorithm during the contest.</p><p>Check <a class=\"rated-user user-violet\" href=\"/profile/rares.buhai\" title=\"Candidate Master rares.buhai\">rares.buhai</a>'s <a href=\"//codeforces.com/contest/346/submission/4520171\">solution</a></p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>The expected solution is evaluating the dp function as the increased value of dp[u] itself. Further analysis shows, wheather we decided sending order or not in u can be judged as the out-degree of u.</p> <pre><code><br />while (!Q.empty()) {\n u = Q.front(), Q.pop_front()\n for each edge from v to u\n --out_degree[v]\n\tif (out_degree[v] == 0) {\n relax dp[v] by dp[u]\n if success, add v to the front of Q\n\t}\n\telse{\n\t relax dp[v] by dp[u] + 1\n\t if success, add v to the back of Q\n }\t\n }\n</code></pre><p>Check <a class=\"rated-user user-orange\" href=\"/profile/Ra16bit\" title=\"International Master Ra16bit\">Ra16bit</a>'s <a href=\"//codeforces.com/contest/346/submission/4519668\">solution</a> to see how it works.</p><h3><a href=\"//codeforces.com/problemset/problem/346/E\">Problem E. Doodle Jump</a></h3><h4>Brief description:</h4><p>You have been give <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>, <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>h</i></span> (gcd(<span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>) = 1), For each <span class=\"tex-span\"><i>ai</i></span> mod <span class=\"tex-span\"><i>p</i></span>, (<span class=\"tex-span\"><i>i</i></span>∈[1, n]), check weather the maximum distance in neighborhood after sorting is <= <span class=\"tex-span\"><i>h</i></span>. </p><h4>Analysis:</h4><p>Take <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 for example ... Divided the numbers in group.</p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 18\n</code></pre><p>We start a new group when the number > P</p><p>We found the difference between the elements of the first group is 5, The subsequent is filling some gap between the them ...</p><p>After some observation we could found that we should only consider into one gap ...(e.g. [0, 5] or [15, 20] or [20, 25] ... ) </p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>That says .. <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 is roughly equal to some things in small scale?</p><p>So let's check it in detail. Lemma 1. In any case, the gap after 20 won't better than any gap before it.</p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>For example, in this case, the gap after 20 is: 20, 22 And it has 16 in [15, 17] but no 21. </p><p>Is there any chance that [20, 23] is better than [15, 20]?</p><p>No, that is because, when there is no 21, then (19+5)%23 = 1, go to next floor. and there is no corresponding gap after 20 ([22, 24]) for this gap ([17, 19])</p><p>So we only need to consider [15, 20] ... and we found [15, 20] is roughly equal to [0, 5]</p> <pre><code>e.g. : 15 20 17 19 16 18 \nequal: 0 5 2 4 1 3\n</code></pre><p>we say 'roughly' because we havn't check some boundary case like there is 3 but on 18 ... </p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 \n</code></pre><p>If it happend, we should remove the number 3. .. If we can remove the element 5, then we can from a=5, p=23 to a'=2, p'=5 ...(n' = an/p, a' = a-p%a, if there is 3 but no 18, n'=n'-1)</p><p>The rest things is to discuss wheather 5 is necessary or not.</p><p>Let's we have:</p> <pre><code>0 2 4\n1 3\n</code></pre><p>If the 2*n'<5, then there is only one floor, the answer is max(2, 5-2*n'). If there is more than one floor, we could conclude that 5 is useless.</p><p>Proof: Elemets in 1st floor is: </p> <pre><code>0 a 2a 3a ...\n</code></pre><p>Let's say the maximum elements in 1st floor is x, then the minimum element in the 2nd floor is b0 = x+a-p, because b0 — a = x-p, so the difference between b0 and a is equal to the difference between x and p. That is, we can consider [b0, a] rather than [x, p], when there is a element insert in [b0, a], there must be some element insert in [x, p] in the same position.</p><p>So we have have succeeded to transform our original problem into a small one. Of couse, this problem havn't been solved, we haven't consider the time complexity. Says a' = a — p%a, when p = a+1, then a' = a-1, but we have <span class=\"tex-span\"><i>a</i></span> equal to 10^9, it won't work.</p><p>But, let's we have A1, A2, ... An ... and we subtract <span class=\"tex-span\"><i>d</i></span> from all of them, the answer won't be changed. So we can use p%a substitute for a-p%a, this is equivalent to we subtract %p% from all of them ...</p><p>So we set a' = min(a-p%a, p%a), so a'<=a/2, therefore, the final time complexity is <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span>.</p><p>You can check <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> <a href=\"//codeforces.com/contest/346/submission/4523388\">'s solution</a> for detail.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/346\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/347\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-4906-8958\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"4906\",\n blogEntryId: \"8903\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+56</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/MinakoKojima\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/MinakoKojima\">\n MinakoKojima\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8903#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8903#comments\">\n 66\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8974\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (56)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146290\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mohammadrdeh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/47/avatar/91eee3f7a5ec41f6.jpg'/> </a>\n <div><a href=\"/profile/mohammadrdeh\" title=\"Specialist mohammadrdeh\" class=\"rated-user user-cyan\">mohammadrdeh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146290\" href=\"?#comment-146290\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146290\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"14\"\r\n data-commentUserId=\"47\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+14</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146290\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>there is a typo: "... the classical <strong>LCA</strong> problem ..." => <strong>LCS</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146290 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146290 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146290\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146291\" commentParentId=\"146290\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146291\" href=\"?#comment-146291\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146290\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146291\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146291\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you. Fixed. m(_ _)m</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146291 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146291 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146291\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146297\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 05:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146297\" href=\"?#comment-146297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Actually our standard solution to C is O(b-a+n). O(b-a+n),O(b-a+nlogn),O((b-a+n)logn) are all able to pass during the test.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146297\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146335\" commentParentId=\"146297\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mmaxio\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/486/avatar/4bb53c24fc9e4c1.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/mmaxio\" title=\"International Master mmaxio\" class=\"rated-user user-orange\">mmaxio</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 17:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146335\" href=\"?#comment-146335\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146297\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146335\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146335\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"486\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146335\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>oh, never mind</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146335 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146335 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146335\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146299\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shashwat.gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6204/avatar/67f8e17c53f70578.jpg'/> </a>\n <div><a href=\"/profile/shashwat.gupta\" title=\"Specialist shashwat.gupta\" class=\"rated-user user-cyan\">shashwat.gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146299\" href=\"?#comment-146299\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146299\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"6204\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146299\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Problem B: Can you Explain little bit more on How "Aho-Corasick automation, or KMP" can help in figuring out smallest string that does not contain virus.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146299 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146299 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146299\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146300\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146300\" href=\"?#comment-146300\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146300\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146300\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For B, I already had the intuitive idea that this problem will be solved by either Aho-Corasick algorithm or KMP with dp, but I could not formalize the idea of states transition in dp. Could you please just provide the state in your dp algorithm?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146300 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146300 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146300\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146354\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146354\" href=\"?#comment-146354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146354\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Original problem can be solved by dp with two parameters DP[Len(s)] [Len(t)]. <a href=\"https://en.wikipedia.org/wiki/Longest_common_subsequence_problem\">http://en.wikipedia.org/wiki/Longest_common_subsequence_problem</a></p><p>To solve B you need to modificate it to DP[Len(s)][Len(t)][Len(virus)-1] where third parameter means maximum length of suffix of LCS that equal to prefix of virus.</p><p>To easy check where we go from K state (third parameter) by character C we can make automat on prefix function by virus.</p><p>Then if we stand in DP[i][j][k] :<br /> 1) if(s[i] == t[j] and Automat[k][c]<Len(virus) we try to relax DP[i+1][j+1][Automat[k][c]]<br /> 2) Try to relax DP[i][j+1][k] and DP[i+1][j][k]</p><p><strong>UPD</strong> My solution: <a href=\"//codeforces.com/contest/346/submission/4532899\">http://codeforces.com/contest/346/submission/4532899</a> (hope it understandable)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146354\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146357\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146357\" href=\"?#comment-146357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>got it, many thanks to you man :) Also understood why KMP tag mentioned in the problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146357\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146493\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lama\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/72190/avatar/735906a91d1576e3.jpg'/> </a>\n <div><a href=\"/profile/lama\" title=\"Expert lama\" class=\"rated-user user-blue\">lama</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 18:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146493\" href=\"?#comment-146493\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146493\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146493\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) Can you please explain what "maximum length of suffix of LCS that equal to prefix of virus" means? 2) What is an automat?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146493 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146493 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146493\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146519\" commentParentId=\"146493\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/25/2013 05:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146519\" href=\"?#comment-146519\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146493\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146519\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146519\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146519\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) We stand in DP[i][j][k]-state (in which we store longest LCS), virus = "virus" <br /> Let's go from k = 0 to 4,then:</p> <pre><code>0) DP[i][j][0] means that finded LCS not ends on "v" or "vi" or "vir" or "viru" or "virus". (example: "a")\n\n1) DP[i][j][1] means that finded LCS ends on "v", but not on "vi" or "vir" or "viru" or "virus". (example: "av")\n\n2) DP[i][j][2] means that finded LCS ends on "vi", but not on "vir" or "viru" or "virus". (example: "avi")\t\n\n3) DP[i][j][3] means that finded LCS ends on "vir", but not on "viru" or "virus". (example: "avir")\n\n4) DP[i][j][4] means that finded LCS ends on "viru", but not on "virus". (example: "aviru")\n\nWe take "longest suffix of LCS that equal prefix of virus", because virus could be: "vvvvv" or "ababv" (and infinite others)\n If LCS = "avvv" - it ends on "v","vv","vvv". (virus = "vvvvv")\n If LCS = "aabab" - it ends on "ab" and "abab". (virus = "ababv")\n</code></pre><p><a href=\"https://en.wikipedia.org/wiki/Knuth%E2%80%93Morris%E2%80%93Pratt_algorithm\">KMP</a></p><p>2) <a href=\"https://en.wikipedia.org/wiki/Automata_theory\">http://en.wikipedia.org/wiki/Automata_theory</a></p><p>Can't find nothing about automaton on prefix-function in english. I hope you will be able understand <a href=\"http://e-maxx.ru/algo/prefix_function\">this</a> with some translator (google translate for example).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146519 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146519 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146519\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"551712\" commentParentId=\"146519\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/srv_twry\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/447741/avatar/d1a80b00eb029c2b.jpg'/> </a>\n <div><a href=\"/profile/srv_twry\" title=\"Expert srv_twry\" class=\"rated-user user-blue\">srv_twry</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/19/2019 12:58\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-551712\" href=\"?#comment-551712\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146519\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"551712\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"447741\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-551712\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Fortunately, the e-maxx article on Prefix function has been translated in English and can be found here: <a href=\"https://cp-algorithms.com/string/prefix-function.html#toc-tgt-12\">prefix-function: automaton on prefix-function</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-551712 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-551712 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-551712\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"768401\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ttbbnnn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1694563/avatar/ff85df0301cf6f76.jpg'/> </a>\n <div><a href=\"/profile/ttbbnnn\" title=\"Master ttbbnnn\" class=\"rated-user user-orange\">ttbbnnn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2021 20:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-768401\" href=\"?#comment-768401\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"768401\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1694563\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-768401\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My solution for B got a WA on test 41 and I don't know why :<, please help me with this code: <a href=\"https://codeforces.com/contest/346/submission/109283664\">https://codeforces.com/contest/346/submission/109283664</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-768401 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-768401 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-768401\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146301\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146301\" href=\"?#comment-146301\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146301\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146301\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146301\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"So the remians work is to delete those same xi, and watch out some situation could cause degeneration. Many of us failed in this last step and got TLE", I really could not understand this. What you you mean by degeneration in this case? Please explain this last important step.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146301 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146301 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146301\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146302\" commentParentId=\"146301\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:37\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146302\" href=\"?#comment-146302\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146301\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146302\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146302\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>suppose b=1, all x[i]>a, what will happen?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146302 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146302 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146302\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146304\" commentParentId=\"146302\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146304\" href=\"?#comment-146304\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146302\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146304\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146304\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As b = 1, All x[i] > a. Then a % x[i] = a. So if we take this, then we will lead to a — a = 0, which is less than b. So we need to move one by one, so answer would be a.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146304 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146304 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146304\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146309\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146309\" href=\"?#comment-146309\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146309\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146309\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Alice and Bob problem how do you prove that you will always get {d, 2d, 3d, ... max{xi}} in the end. It is easy to see but I am unable to prove it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146309 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146309 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146309\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146365\" commentParentId=\"146309\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marat.snowbear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98082/avatar/1499cf6d0c86172.jpg'/> </a>\n <div><a href=\"/profile/marat.snowbear\" title=\"International Master marat.snowbear\" class=\"rated-user user-orange\">marat.snowbear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146365\" href=\"?#comment-146365\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146309\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146365\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"98082\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146365\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I convinced myself like this:</p> <ol> <li>Prove that we will be able to get d by some sequence of subtractions.</li> <li>Prove that we will be able to generate {d, 2d, 3d, ...}</li> <li>Prove that we will not be able to get anything else except for { d, 2d, 3d, ... }</li> </ol><p>In details:</p> <ol> <li><p>See <a href=\"https://en.wikipedia.org/wiki/Euclidean_algorithm\">Euclidean algorithm for finding GCD</a>. If you will look into the description or code you will see that it does exactly what is asked in this problem — subtracts numbers one from another. And the result is GCD of original two numbers. So you can see that by some sequence of subtractions you can get GCD.</p></li> <li><p>If you already have d which GCD of all the numbers then you can easily fill all the gaps in { d, 2d, 3d, ..., max } sequence by starting subtracting d from { max, max — d, max — 2d, ... }. So you will get the intended set.</p></li> <li><p>You cannot subtract two numbers a and b which have GCD(a, b) = d and get result which won't be dividable by d. So if you start with set where every numbers can be divided by d then no matter what you subtract you will always have the result which is also dividable by d.</p></li> </ol></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146365 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146365 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146365\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146390\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 16:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146390\" href=\"?#comment-146390\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146390\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146390\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, got it. Thanks!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146390 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146390 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146390\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"774539\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/25/2021 20:24\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-774539\" href=\"?#comment-774539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"774539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-774539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-774539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-774539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-774539\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146310\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i_coder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i_coder\" title=\"Expert i_coder\" class=\"rated-user user-blue\">i_coder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146310\" href=\"?#comment-146310\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146310\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"41979\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146310\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Is this the final editorial (except the D problem) ? The explanations to problems B and C are very limited and not at all well elaborated.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146310 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146310 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146310\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146314\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146314\" href=\"?#comment-146314\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146314\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146314\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can you tell me that why the number of rounds in Problem A will be max(xi)/d-n ? How do you come to this point ? can you please tell me this as am not to figure out this thing ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146314 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146314 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146314\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146316\" commentParentId=\"146314\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:45\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146316\" href=\"?#comment-146316\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146314\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146316\" revisionCount=\"7\" revision=\"7\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">7</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146316\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146316\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>take example <br /> 3 9 54 <br /> gcd (3, 9, 54) = 3 <br /> Now total rounds possible including (3, 9, 54) =<br />all multiples of 3 upto 54 <br /> 3, 6, 9, 12, 15, 18 ... 54 <br /> </p><p>So total count of these numbers = 54 / 3 = 18. <br /> </p><p>Now as out of these numbers 3 numbers are already taken, so subtract 3 <br /> so rounds remaining = 18 — 3 = 15 </p><p>Now it is very easy to generalize for 3 being d and 54 being n</p><p>answer would be n / d — n. <br /> I hope it is clear now :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146316 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146316 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146316\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146319\" commentParentId=\"146316\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146319\" href=\"?#comment-146319\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146316\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146319\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146319\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes, it is more clear to me now. but one thing is that how did you approach to gcd thing ? I understood the problem, the logic and all. how did you approach that it will be done using gcd thing and all ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146319 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146319 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146319\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146322\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146322\" href=\"?#comment-146322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146322\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My Ideas during solving the problem: <br /> all the examples had gcd 1. So I directly thought answer as max(xi) — n. <br /> But I thought it can not be too simple, I need to think more. <br /> So I took a case 2 4 6, I immediately found I am wrong in this case. <br /> Then the idea came into mind that if gcd of numbers is g. then we can not create any number not divisible by g because (g *k1 — k * k2) = g * (k1 — k2). </p><p>So Finally I coded it and got accpeted :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146322\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146338\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 19:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146338\" href=\"?#comment-146338\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146338\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146338\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>given the numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>, what is the minimum positive value you can achieve by combining them? </p><p>Let's write down the equation: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>·<i>x</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub>·<i>x</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>n</i></sub>·<i>x</i><sub class=\"lower-index\"><i>n</i></sub> = <i>d</i></span>, where <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> are some unknown integers. </p><p>It is, as you can see, none other than linear Diophantine equation. And it is known there is no solutions if <span class=\"tex-span\"><i>d</i></span> is not a multiple of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span> </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146338 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146338 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146338\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146317\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/subway\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123924/avatar/706e86f587cbabf0.jpg'/> </a>\n <div><a href=\"/profile/subway\" title=\"Expert subway\" class=\"rated-user user-blue\">subway</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146317\" href=\"?#comment-146317\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146317\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146317\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@hellodear-the final set will contain all elements {d,2d,3d,..max(Xi)} (d=gcd of all elements) so total no. of elements in final set =max(Xi)/d since initially we have 'n' elements total no. of new elements to be added in set to make it complete=(max(Xi)/d)-n.. hope this helps you..:)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146317 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146317 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146317\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146320\" commentParentId=\"146317\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146320\" href=\"?#comment-146320\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146317\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146320\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146320\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in this thing, I was applying some game theory, but it doesn't include anything like that. when the question says optimally, then how do you form examples so as to test your code on them ? because optimally means in the best they can. can you elaborate ? thanks to you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146320 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146320 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146320\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146324\" commentParentId=\"146320\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146324\" href=\"?#comment-146324\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146320\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146324\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146324\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146324\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>optimality argument is simple and also given in the editorial itself. <br /> As total you numbers finally would be {d, 2 * d,, .,, max (xi)}. <br /> Hence whatever you add to the these set, no other person will be able to add that as he has to add a new number everytime to this test. <br /> So outcome depend on the parity of turns.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146324 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146324 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146324\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146325\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sinamosavi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/87557/avatar/bde58fa97bcc5eb0.jpg'/> </a>\n <div><a href=\"/profile/sinamosavi\" title=\"Pupil sinamosavi\" class=\"rated-user user-green\">sinamosavi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146325\" href=\"?#comment-146325\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146325\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"87557\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146325\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the complete proof for A.Div1 is not that much straightforward. Maybe I'm making it too much difficult, but this is my complete proof:</p><p>First by induction, we prove that the numbers in the end will be <span class=\"tex-span\"><i>a</i>, 2<i>a</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Let <span class=\"tex-span\"><i>g</i> = <i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ... , <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span>. It's trivial that in the end <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>. Assume that <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>, because our numbers will be <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), 2<i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>, so we would have a new gcd. That's a contradiction, so <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) = <i>g</i></span> and our numbers will be <span class=\"tex-span\"><i>g</i>, 2<i>g</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Each move adds one number and in the end there will be <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e6ac12549498d8aaad3d63270d12497bc74a9f84.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> numbers, so the answer wil be the parity of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/48ba1bfd0fa315ab1595947b8e046b4cc211b908.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Sorry for my bad English.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146325 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146325 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146325\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146332\" commentParentId=\"146325\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146332\" href=\"?#comment-146332\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146325\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146332\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-13\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146332\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What about this test <code>2 3 5</code>? <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≠ <i>gcd</i></span></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146332 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146332 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146332\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146333\" commentParentId=\"146332\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146333\" href=\"?#comment-146333\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146332\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146333\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146333\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Oops. You've meant that <span class=\"tex-span\"><i>a</i></span> — is the result. Sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146333 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146333 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146333\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146334\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 16:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146334\" href=\"?#comment-146334\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146334\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146334\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146334\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>But how to prove that there is always a way to choose <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> while the number of the current round less than the maximum number of rounds? (Div2C)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146334 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146334 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146334\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146339\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:22\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146339\" href=\"?#comment-146339\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146339\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146339\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146339\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If gcd{xi}＝1, then for every xi there must exist ti to make sum｛xi*ti｝＝1. </p><p>(For example, x1＝5,x2＝7,then t1＝3,t2＝-2.x1*t1＋x2*t2＝1.)</p><p>And sum{xi*ti} can be performed in a few turns. ( (5-(7-5))-(7-5). )</p><p>And if we can get 1, then what number between [1,max{xi}] can't we get？</p><p>if gcd{xi}≠1.the proof is similar.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146339 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146339 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146339\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146341\" commentParentId=\"146339\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146341\" href=\"?#comment-146341\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146339\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146341\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146341\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why there is must exist such t[i]?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146341 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146341 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146341\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146366\" commentParentId=\"146341\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146366\" href=\"?#comment-146366\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146341\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146366\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146366\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You must know if gcd(a,b)＝1, there must exist x and y to make ax＋by＝1. It can be proved from this.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146366 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146366 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146366\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146376\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146376\" href=\"?#comment-146376\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146376\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146376\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146376\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So.. If we divide all the numbers by GCD, and after that a pair of coprime numbers have appeared, we always can reach 1. Let's choose coprime <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, then <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> will be also coprime with <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, and it will be less then <span class=\"tex-span\"><i>max</i>(<i>x</i>, <i>y</i>)</span>. So we can choose <span class=\"tex-span\"><i>mid</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>x</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>min</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>y</i><sub class=\"lower-index\">1</sub></span>, and they are coprime, and <span class=\"tex-span\">|<i>x</i><sub class=\"lower-index\">1</sub> - <i>y</i><sub class=\"lower-index\">1</sub>|</span> will be less than <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>. And etc. by induction. But what to do if there is not a pair of coprime numbers after dividing by GCD? For example <code>35 45 63</code>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146376 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146376 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146376\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146404\" commentParentId=\"146376\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146404\" href=\"?#comment-146404\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146376\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146404\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146404\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146404\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>63*2＋45*5＋35*(-10)＝1</p><p>Because gcd (35,45)＝5, we can consider 35 and 45 as one number 5x. Because gcd(5,63)＝1, so there must exist x,y to make 5x＋63y＝1.</p><p>So here comes a tragedy. We can get 5 first. Then we use this number together with 63 to make 1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146404 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146404 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146404\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146346\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KiAsaGibona\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/KiAsaGibona\" title=\"Specialist KiAsaGibona\" class=\"rated-user user-cyan\">KiAsaGibona</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 21:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146346\" href=\"?#comment-146346\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146346\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146346\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"99053\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146346\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Someone please explain the greedy idea of (Div 1 C) (Number Transformation II). Thanks in advance :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146346 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146346 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146346\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146367\" commentParentId=\"146346\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 09:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146367\" href=\"?#comment-146367\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146346\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146367\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146367\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's a pretty simple greedy idea: Just pick the <code>x</code> that makes the value of <code>a</code> smallest after applying the operation <code>a = a - a%x</code> (or subtract 1 if no choice for <code>x</code> makes <code>a</code> smaller). The proof why this works is given in the editorial: it is never better to get a larger number, so you should get the smallest one you can.</p><p>As listed on the last paragraph of the editorial you have to be careful to remove all <code>x</code> that are either duplicates or cannot be used anymore (<code>a - (a%x)</code> is smaller than <code>b</code>), otherwise you will get TLE.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146367 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146367 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146367\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146382\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146382\" href=\"?#comment-146382\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146382\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146382\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146382\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>how to find this x for each number?</p><p>we will iterate on all x[i]s and only delete x[i]s when x[i] > a?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146382 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146382 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146382\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146405\" commentParentId=\"146382\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146405\" href=\"?#comment-146405\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146382\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146405\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146405\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Iterate through all x[i]s and delete them when a — (a%x[i]) is smaller than b (if you only delete when x[i] > a, you will also get TLE).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146405 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146405 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146405\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146625\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 17:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146625\" href=\"?#comment-146625\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146625\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146625\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm really striving to understand why the algorithm turns out to be linear instead of quadratic... I know the editorial says "That is because, we could cut exactly <span class=\"tex-span\"><i>max</i>{<i>xi</i>}</span> in each 2 step.", but I can't really get what it means :\\</p><p>Can you give me a hint? Thanks :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146625 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146625 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146625\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146643\" commentParentId=\"146625\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/xenoslash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88090/avatar/f75f8cbc20d6133f.jpg'/> </a>\n <div><a href=\"/profile/xenoslash\" title=\"Expert xenoslash\" class=\"rated-user user-blue\">xenoslash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 19:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146643\" href=\"?#comment-146643\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146625\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146643\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146643\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"88090\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146643\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have an easy intuition of cutting at least max{xi} in O(1) steps, not sure what was the intended 2 step proofs though. I am going to use xi to refer to max{xi}, and assume that proper care is taken to only keep the relevant xi's.</p><p>When we do a-(a % xi), we bring caused a to be the next largest integer <= a that is a multiple of xi, since now new_a % xi = 0. Then, if a is divisible by xi, you can do.., do a-1 (causing it to be non-divisible by xi), then finally a-(a%xi) again. In this 3 step sequence you have brought a down to the next lower multiple of xi, and have essentially cut max{xi} in O(1) number of steps.</p><p>Sample code : <a href=\"//codeforces.com/contest/346/submission/4545367\">http://codeforces.com/contest/346/submission/4545367</a> Yeah I used tree set so it's not exactly O(n).. but hash set keeps giving me TLE :(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146643 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146643 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146643\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146689\" commentParentId=\"146643\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2013 12:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146689\" href=\"?#comment-146689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146643\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you very much, that was really eye-opening! This is why I love Codeforces, great community! :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146689\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146371\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Corvo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/11909/avatar/8404ac1aff5270ec.jpg'/> </a>\n <div><a href=\"/profile/Corvo\" title=\"Pupil Corvo\" class=\"rated-user user-green\">Corvo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 12:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146371\" href=\"?#comment-146371\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146371\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"11909\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146371\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please explain why the problem is solved through the GDC (A)? I tried like <a href=\"https://codeforces.com/contest/347/submission/4535232\">this</a>, but I still can not understand why you can not do. Please give a short test on which the decision falls. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146371 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146371 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146371\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146375\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146375\" href=\"?#comment-146375\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146375\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146375\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><pre><code>3\n14 4 2\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146375 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146375 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146375\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146378\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akashdeep\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/39866/avatar/6f66d1bbe26ef4ca.jpg'/> </a>\n <div><a href=\"/profile/akashdeep\" title=\"International Master akashdeep\" class=\"rated-user user-orange\">akashdeep</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146378\" href=\"?#comment-146378\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146378\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"39866\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146378\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Because only those numbers are possible in the game which are multiple of gcd. See this simplest test case</p> <pre><code>2\n4 6\n</code></pre><p>The only number possible in the game is (6-4) i.e. 2, but in your code u are assuming that somehow these (1,2,3,5) numbers can be obtained which is a wrong assumption.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146378 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146378 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146378\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146408\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/NegaTeeF\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/NegaTeeF\" title=\"Master NegaTeeF\" class=\"rated-user user-orange\">NegaTeeF</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 20:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146408\" href=\"?#comment-146408\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146408\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"65829\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146408\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Explain please, how to do Div1-D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146408 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146408 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146408\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146410\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/irakli_p\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29034/avatar/d879a3156498c6c7.jpg'/> </a>\n <div><a href=\"/profile/irakli_p\" title=\"Expert irakli_p\" class=\"rated-user user-blue\">irakli_p</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 21:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146410\" href=\"?#comment-146410\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146410\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29034\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146410\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i didn't understand Div 2 — D can someone explain it to me please </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146410 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146410 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146410\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146443\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/suiyuan2009\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49923/avatar/9065a92c0b30b883.jpg'/> </a>\n <div><a href=\"/profile/suiyuan2009\" title=\"Master suiyuan2009\" class=\"rated-user user-orange\">suiyuan2009</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 13:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146443\" href=\"?#comment-146443\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146443\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49923\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146443\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>problem B,ac automachine is doing the thing that belong to kmp</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146443 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146443 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146443\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146452\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 17:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146452\" href=\"?#comment-146452\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146452\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146452\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div1_E: Should the "Doodler" jump over the platform which H = P ? I just confused about that.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146452 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146452 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146452\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146480\" commentParentId=\"146452\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 11:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146480\" href=\"?#comment-146480\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146452\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146480\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146480\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OK I got the answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146480 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146480 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146480\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146463\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146463\" href=\"?#comment-146463\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146463\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"44\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+44</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146463\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>still waiting for D tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146463 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146463 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146463\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147566\" commentParentId=\"146463\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/05/2013 05:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147566\" href=\"?#comment-147566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146463\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>.. Update .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147566\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"235917\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/saurabhverma\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/143428/avatar/48808a8d5db775d4.jpg'/> </a>\n <div><a href=\"/profile/saurabhverma\" title=\"Expert saurabhverma\" class=\"rated-user user-blue\">saurabhverma</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2015 20:05\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-235917\" href=\"?#comment-235917\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"235917\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"143428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-235917\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In my approach to problem div1 B, I calculated longest common subsequence, prepended virus to it, calculated the Z function and deleted every character which had z[i] >= virus.size(). I don't think my approach is wrong. Can someone tell me if my code is wrong or the approach has some flaw. Thanks. Submission : <a href=\"//codeforces.com/contest/346/submission/11491420\">http://codeforces.com/contest/346/submission/11491420</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-235917 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-235917 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-235917\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"530287\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arpit4427\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/717924/avatar/90dcbc94a1e57cf.jpg'/> </a>\n <div><a href=\"/profile/arpit4427\" title=\"Expert arpit4427\" class=\"rated-user user-blue\">arpit4427</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/26/2019 14:04\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-530287\" href=\"?#comment-530287\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"530287\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"530287\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"717924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-530287\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone explain how to solve this problem <a href=\"/contest/346/problem/B\" title=\"Codeforces Round 201 (Div. 1)\">346B - Lucky Common Subsequence</a>? I have went thorugh the editorial but I could not understand.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-530287 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-530287 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-530287\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8974\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8974 = true;\r\nvar lastPreviewContent8974 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8974] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8974] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:24</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812874998e81759f',t:'MTY5NjcwNTk0NS4wMjkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1751,"cells":{"problem_id":{"kind":"string","value":"346E"},"contest":{"kind":"string","value":"346"},"problem":{"kind":"string","value":"E"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"E. Doodle Jump"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Doodle Jump</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p><span class=\"tex-font-style-underline\"> In Doodle Jump the aim is to guide a four-legged creature called \"The Doodler\" up a never-ending series of platforms without falling. — Wikipedia. </span></p><p>It is a very popular game and xiaodao likes it very much. One day when playing the game she wondered whether there exists a platform that the doodler couldn't reach due to the limits of its jumping ability. Consider the following problem.</p><p>There are <span class=\"tex-span\"><i>n</i></span> platforms. The height of the <span class=\"tex-span\"><i>x</i></span>-th (<span class=\"tex-span\">1 ≤ <i>x</i> ≤ <i>n</i></span>) platform is <span class=\"tex-span\"><i>a</i>·<i>x</i></span> mod <span class=\"tex-span\"><i>p</i></span>, where <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>p</i></span> are positive co-prime integers. The maximum possible height of a Doodler's jump is <span class=\"tex-span\"><i>h</i></span>. That is, it can jump from height <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub></span> to height <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">2</sub></span> (<span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub> < <i>h</i><sub class=\"lower-index\">2</sub></span>) if <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">2</sub> - <i>h</i><sub class=\"lower-index\">1</sub> ≤ <i>h</i></span>. Initially, the Doodler is on the ground, the height of which is 0. The question is whether it can reach the highest platform or not.</p><p>For example, when <span class=\"tex-span\"><i>a</i> = 7</span>, <span class=\"tex-span\"><i>n</i> = 4</span>, <span class=\"tex-span\"><i>p</i> = 12</span>, <span class=\"tex-span\"><i>h</i> = 2</span>, the heights of the platforms are <span class=\"tex-span\">7</span>, <span class=\"tex-span\">2</span>, <span class=\"tex-span\">9</span>, <span class=\"tex-span\">4</span> as in the picture below. With the first jump the Doodler can jump to the platform at height <span class=\"tex-span\">2</span>, with the second one the Doodler can jump to the platform at height <span class=\"tex-span\">4</span>, but then it can't jump to any of the higher platforms. So, it can't reach the highest platform.</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/81c2accb85ac208c2bf9266faa725f984619af6e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>User xiaodao thought about the problem for a long time but didn't solve it, so she asks you for help. Also, she has a lot of instances of the problem. Your task is solve all of these instances.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>t</i></span> <span class=\"tex-span\">(1 ≤ <i>t</i> ≤ 10<sup class=\"upper-index\">4</sup>)</span> — the number of problem instances. Each of the next <span class=\"tex-span\"><i>t</i></span> lines contains four integers <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>p</i></span> and <span class=\"tex-span\"><i>h</i></span> (<span class=\"tex-span\">1 ≤ <i>a</i> ≤ 10<sup class=\"upper-index\">9</sup></span>, <span class=\"tex-span\">1 ≤ <i>n</i> < <i>p</i> ≤ 10<sup class=\"upper-index\">9</sup></span>, <span class=\"tex-span\">0 ≤ <i>h</i> ≤ 10<sup class=\"upper-index\">9</sup></span>). It's guaranteed that <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>p</i></span> are co-prime.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each problem instance, if the Doodler can reach the highest platform, output \"<span class=\"tex-font-style-tt\">YES</span>\", otherwise output \"<span class=\"tex-font-style-tt\">NO</span>\".</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>7 4 12 2<br/>7 1 9 4<br/>7 4 12 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO<br/>NO<br/>YES<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"b72125e7bb4ceb88e20f65337ab5de4b\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"76ca6f0bbc2c68c0c469d82a1a1c06e9e639f443\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='b72125e7bb4ceb88e20f65337ab5de4b'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F346%2Fproblem%2FE%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='b72125e7bb4ceb88e20f65337ab5de4b'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/346\">Codeforces Round 201 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='b72125e7bb4ceb88e20f65337ab5de4b'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/346/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Number theory: Euler function, GCD, divisibility, etc\">\r\n number theory\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *3000\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='b72125e7bb4ceb88e20f65337ab5de4b'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3507\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='b72125e7bb4ceb88e20f65337ab5de4b'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3507\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8896\" title=\"Codeforces Round #201\" target=\"_blank\">Codeforces Round #201</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1860:1861\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8903\" title=\"Codeforces Round #201 Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1864\" resourceName=\"Codeforces Round #201 Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/346\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/346/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/346/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/346/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/346/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/346/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/346/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/346/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_7242767c8fa45246a7a4a1c15ade216784711a8e\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Doodle Jump</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p><span class=\"tex-font-style-underline\"> In Doodle Jump the aim is to guide a four-legged creature called "The Doodler" up a never-ending series of platforms without falling. — Wikipedia. </span></p><p>It is a very popular game and xiaodao likes it very much. One day when playing the game she wondered whether there exists a platform that the doodler couldn't reach due to the limits of its jumping ability. Consider the following problem.</p><p>There are <span class=\"tex-span\"><i>n</i></span> platforms. The height of the <span class=\"tex-span\"><i>x</i></span>-th (<span class=\"tex-span\">1 ≤ <i>x</i> ≤ <i>n</i></span>) platform is <span class=\"tex-span\"><i>a</i>·<i>x</i></span> mod <span class=\"tex-span\"><i>p</i></span>, where <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>p</i></span> are positive co-prime integers. The maximum possible height of a Doodler's jump is <span class=\"tex-span\"><i>h</i></span>. That is, it can jump from height <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub></span> to height <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">2</sub></span> (<span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub> < <i>h</i><sub class=\"lower-index\">2</sub></span>) if <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">2</sub> - <i>h</i><sub class=\"lower-index\">1</sub> ≤ <i>h</i></span>. Initially, the Doodler is on the ground, the height of which is 0. The question is whether it can reach the highest platform or not.</p><p>For example, when <span class=\"tex-span\"><i>a</i> = 7</span>, <span class=\"tex-span\"><i>n</i> = 4</span>, <span class=\"tex-span\"><i>p</i> = 12</span>, <span class=\"tex-span\"><i>h</i> = 2</span>, the heights of the platforms are <span class=\"tex-span\">7</span>, <span class=\"tex-span\">2</span>, <span class=\"tex-span\">9</span>, <span class=\"tex-span\">4</span> as in the picture below. With the first jump the Doodler can jump to the platform at height <span class=\"tex-span\">2</span>, with the second one the Doodler can jump to the platform at height <span class=\"tex-span\">4</span>, but then it can't jump to any of the higher platforms. So, it can't reach the highest platform.</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/81c2accb85ac208c2bf9266faa725f984619af6e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>User xiaodao thought about the problem for a long time but didn't solve it, so she asks you for help. Also, she has a lot of instances of the problem. Your task is solve all of these instances.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>t</i></span> <span class=\"tex-span\">(1 ≤ <i>t</i> ≤ 10<sup class=\"upper-index\">4</sup>)</span> — the number of problem instances. Each of the next <span class=\"tex-span\"><i>t</i></span> lines contains four integers <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>p</i></span> and <span class=\"tex-span\"><i>h</i></span> (<span class=\"tex-span\">1 ≤ <i>a</i> ≤ 10<sup class=\"upper-index\">9</sup></span>, <span class=\"tex-span\">1 ≤ <i>n</i> < <i>p</i> ≤ 10<sup class=\"upper-index\">9</sup></span>, <span class=\"tex-span\">0 ≤ <i>h</i> ≤ 10<sup class=\"upper-index\">9</sup></span>). It's guaranteed that <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>p</i></span> are co-prime.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each problem instance, if the Doodler can reach the highest platform, output "<span class=\"tex-font-style-tt\">YES</span>", otherwise output "<span class=\"tex-font-style-tt\">NO</span>".</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />7 4 12 2<br />7 1 9 4<br />7 4 12 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO<br />NO<br />YES<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:52</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bde3fe153a55',t:'MTY5NjY0NjAzMi4wODEwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Mathematics including integration, differential equations, etc\", \"Number theory: Euler function, GCD, divisibility, etc\"]"},"short_tags":{"kind":"string","value":"[\"math\", \"number theory\", \"*3000\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8903"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"1c88316eb9ff5851524d80ea59ef3f32\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #201 Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #201 Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='1c88316eb9ff5851524d80ea59ef3f32'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8903\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/MinakoKojima\">MinakoKojima</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/MinakoKojima\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/MinakoKojima\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/MinakoKojima\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/MinakoKojima\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/MinakoKojima\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/MinakoKojima\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/MinakoKojima\" style=\"text-decoration:none;color:black !important;\">MinakoKojima's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8958\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8903\"> <p>Codeforces Round #201 Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a>,\r\n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><img alt=\" \" src=\"/predownloaded/41/3f/413f7303374a112dddc1e63e29cfc12924514cd7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><h1>Overview</h1><p>In DIV 1, there are 4 interesting problems together with a normal one. We think it is reasonable because we can't have a round fullly with intelligence. Problem A, C have weak pretests while others intended to be strong. About more then 200 participants solve A in the early 45mins, then a few of them start from C while most of the other start from B. </p><p>Problem B is a rather standard problem, but if you're unfamiliar with the algorithm, it can be very hard. Problem C is a more intersting problem. As the name implies, there was <a href=\"//codeforces.com/problemset/problem/251/C\">a similar version</a> in the previous round before, but this time it has a brand new constrains.(So here we have a psychology experiment: could different constrains make people thinking in a slightly different way?ww)</p><p>The standard solution of problem C is <span class=\"tex-span\"><i>O</i>((<i>b</i> - <i>a</i>) + <i>nlogn</i>)</span>. The first expected correct solution was written by <a class=\"rated-user user-orange\" href=\"/profile/zeliboba\" title=\"International Master zeliboba\">zeliboba</a>. <a href=\"//codeforces.com/contest/346/submission/4512654\">http://codeforces.com/contest/346/submission/4512654</a></p><p>After that, some people start to solve problem D. Problem D looks like a hard dp problem on a graph at the first glance, the key point is how to avoid the circle in the transfer equation. It turn out to be elegant after you could found a right order of the evaluation. Problem E is challenging which you need find a way to transform the original question into a smaller scale, and cut off many many corner cases ... And in the very end, you find a way like binary search to get <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span> as the time complexity. No one manage to solve problem E during the contest, maybe <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> is the man who closest to it.</p><p>The winner comes to <a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"Grandmaster cgy4ever\">cgy4ever</a>, because he found the draw-black in his previous C submission during the very beginning even when there is nobody hack him! He resubmit it decisively and get back when finished problem D. After that, he use the same trick which made him failed before to hack others and got a handsomely rewards. The second place went to <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a>, because of the combination of decent speed in A, B, C, D.</p><p>Problem B belongs to me, problem C belongs to <a class=\"rated-user user-violet\" href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\">CMHJT</a> and others belong to <a class=\"rated-user user-orange\" href=\"/profile/UESTC_Nocturne\" title=\"International Master UESTC_Nocturne\">UESTC_Nocturne</a>. The illustrator of problem C is <a href=\"http://www.pixiv.net/member_illust.php?mode=medium&illust_id=38602657\">Chairman Miao(貓主席)</a>.</p><h1>Editorial</h1><h3><a href=\"//codeforces.com/problemset/problem/346/A\">Problem A. Alice and Bob</a></h3><h4>Brief description:</h4><p>Alice and Bob play a game, the rules are as follows: First, they will get a set of <span class=\"tex-span\"><i>n</i></span> distinct numbers. And then they take turns to do the following operations. During each operation, either Alice or Bob can choose two different numbers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> from the set, as long as <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> is not in the set, then they add it to the set. The person who can not choose two numbers successfully will lose the game. The question is who will finally win the game if both of them do operations optimally. Remember that Alice always goes first.</p><h4>Analysis:</h4><p>First, no matter what happend, the number set we get at the very endding will be same all the time. Let's say <span class=\"tex-span\"><i>d</i> = <i>gcd</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}. Then the set in the endding will be some things like {<span class=\"tex-span\"><i>d</i></span>, <span class=\"tex-span\">2<i>d</i></span>, <span class=\"tex-span\">3<i>d</i></span>, ... <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}}. So there is always <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub>} / <i>d</i></span> — <span class=\"tex-span\"><i>n</i></span> rounds. And what we should do rest is to check the parity of this value.</p><h3><a href=\"//codeforces.com/problemset/problem/346/B\">Problem B. Lucky Common Subsequence</a></h3><h4>Brief description:</h4><p>You have been given two strings <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and <span class=\"tex-span\"><i>virus</i></span>, and you have to find the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> without <span class=\"tex-span\"><i>virus</i></span> as a substring.</p><h4>Analysis:</h4><p>This is a rather classical problem, let's say if there is no virus, then it is the classical **LCS ** problem. You can solve this by a <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> dynamic programing.</p><p>When consider about the virus, we should add 1 more dimension on the state to trace the growth of the virus. It can be done by wheather <strong>Aho-Corasick automation</strong>, or <strong>KMP</strong> when there is only one virus in this case. The overall time complexity is <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">3</sup>)</span>.</p><h3><a href=\"//codeforces.com/problemset/problem/346/C\">Problem C. Number Transformation II</a></h3><h4>Brief description:</h4><p>You have a number <span class=\"tex-span\"><i>b</i></span>, and want to minus it to <span class=\"tex-span\"><i>a</i></span>, what you can do in each step is weather subtract 1 or <span class=\"tex-span\"><i>b</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> from <span class=\"tex-span\"><i>b</i></span>. And we ask what is the minimum number of steps you need.</p><h4>Analysis:</h4><p>I bet there is a few people know the greedy method even if he/she have solved the early version before.</p><p><a href=\"//codeforces.com/problemset/problem/251/C\">Codeforces #153 Div 1. Problem C. Number Transformation</a></p><p>Let dp[k] denotes the minimum number of steps to transform b+k to b. In each step, you could only choose i which makes b+k-(b+k) mod x[i] minimal to calc dp[k]. It works bacause dp[0..k-1] is a monotone increasing function. Proof: - Say dp[k]=dp[k-t]+1.If t==1, then dp[0..k] is monotone increasing obviously.Otherwise dp[k-1]<=dp[k-t]+1=dp[k] (there must exist a x[i] makes b+k-1 also transform to b+k-t,and it is not necessarily the optimal decision of dp[k-1]). So dp[k] is a monotone increasing function, we can greedily calc dp[a-b].</p><p>In the first glance, it looks like something which will run in square complexity. But actually is linear. That is because, we could cut exactly max{<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>} in each 2 step. It can be proof by induction.</p><p>So the remians work is to delete those same <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>, and watch out some situation could cause degeneration. Many of us failed in this last step and got <strong>TLE</strong></p><h3><a href=\"//codeforces.com/problemset/problem/346/D\">Problem D. Robot Control</a></h3><p>Let's dp from t to s.</p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>Here dp[u] means, the minimum number of orders mzry1992 needs to send in the worst case. The left-hand-side is sending order while the right-hand side is not. At the beginning, we have dp[t] = 1, and dp[s] will be the answer.</p><p>We can see there is circular dependence in this equation, in this situation, one standard method is using Bellman-Ford algorithm to evaluate the dp function.</p><p>But it is not appropriate for this problem.</p><p>(In fact, we add a part of targeted datas in pretest, these datas are enough to block most of our <a href=\"https://en.wikipedia.org/wiki/Bellman%E2%80%93Ford_algorithm\">Bellman-Ford algorithm</a>, although there is still a few participator can get accepted by Bellman-Ford algorithm during the contest.</p><p>Check <a class=\"rated-user user-violet\" href=\"/profile/rares.buhai\" title=\"Candidate Master rares.buhai\">rares.buhai</a>'s <a href=\"//codeforces.com/contest/346/submission/4520171\">solution</a></p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>The expected solution is evaluating the dp function as the increased value of dp[u] itself. Further analysis shows, wheather we decided sending order or not in u can be judged as the out-degree of u.</p> <pre><code><br />while (!Q.empty()) {\n u = Q.front(), Q.pop_front()\n for each edge from v to u\n --out_degree[v]\n\tif (out_degree[v] == 0) {\n relax dp[v] by dp[u]\n if success, add v to the front of Q\n\t}\n\telse{\n\t relax dp[v] by dp[u] + 1\n\t if success, add v to the back of Q\n }\t\n }\n</code></pre><p>Check <a class=\"rated-user user-orange\" href=\"/profile/Ra16bit\" title=\"International Master Ra16bit\">Ra16bit</a>'s <a href=\"//codeforces.com/contest/346/submission/4519668\">solution</a> to see how it works.</p><h3><a href=\"//codeforces.com/problemset/problem/346/E\">Problem E. Doodle Jump</a></h3><h4>Brief description:</h4><p>You have been give <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>, <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>h</i></span> (gcd(<span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>) = 1), For each <span class=\"tex-span\"><i>ai</i></span> mod <span class=\"tex-span\"><i>p</i></span>, (<span class=\"tex-span\"><i>i</i></span>∈[1, n]), check weather the maximum distance in neighborhood after sorting is <= <span class=\"tex-span\"><i>h</i></span>. </p><h4>Analysis:</h4><p>Take <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 for example ... Divided the numbers in group.</p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 18\n</code></pre><p>We start a new group when the number > P</p><p>We found the difference between the elements of the first group is 5, The subsequent is filling some gap between the them ...</p><p>After some observation we could found that we should only consider into one gap ...(e.g. [0, 5] or [15, 20] or [20, 25] ... ) </p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>That says .. <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 is roughly equal to some things in small scale?</p><p>So let's check it in detail. Lemma 1. In any case, the gap after 20 won't better than any gap before it.</p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>For example, in this case, the gap after 20 is: 20, 22 And it has 16 in [15, 17] but no 21. </p><p>Is there any chance that [20, 23] is better than [15, 20]?</p><p>No, that is because, when there is no 21, then (19+5)%23 = 1, go to next floor. and there is no corresponding gap after 20 ([22, 24]) for this gap ([17, 19])</p><p>So we only need to consider [15, 20] ... and we found [15, 20] is roughly equal to [0, 5]</p> <pre><code>e.g. : 15 20 17 19 16 18 \nequal: 0 5 2 4 1 3\n</code></pre><p>we say 'roughly' because we havn't check some boundary case like there is 3 but on 18 ... </p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 \n</code></pre><p>If it happend, we should remove the number 3. .. If we can remove the element 5, then we can from a=5, p=23 to a'=2, p'=5 ...(n' = an/p, a' = a-p%a, if there is 3 but no 18, n'=n'-1)</p><p>The rest things is to discuss wheather 5 is necessary or not.</p><p>Let's we have:</p> <pre><code>0 2 4\n1 3\n</code></pre><p>If the 2*n'<5, then there is only one floor, the answer is max(2, 5-2*n'). If there is more than one floor, we could conclude that 5 is useless.</p><p>Proof: Elemets in 1st floor is: </p> <pre><code>0 a 2a 3a ...\n</code></pre><p>Let's say the maximum elements in 1st floor is x, then the minimum element in the 2nd floor is b0 = x+a-p, because b0 — a = x-p, so the difference between b0 and a is equal to the difference between x and p. That is, we can consider [b0, a] rather than [x, p], when there is a element insert in [b0, a], there must be some element insert in [x, p] in the same position.</p><p>So we have have succeeded to transform our original problem into a small one. Of couse, this problem havn't been solved, we haven't consider the time complexity. Says a' = a — p%a, when p = a+1, then a' = a-1, but we have <span class=\"tex-span\"><i>a</i></span> equal to 10^9, it won't work.</p><p>But, let's we have A1, A2, ... An ... and we subtract <span class=\"tex-span\"><i>d</i></span> from all of them, the answer won't be changed. So we can use p%a substitute for a-p%a, this is equivalent to we subtract %p% from all of them ...</p><p>So we set a' = min(a-p%a, p%a), so a'<=a/2, therefore, the final time complexity is <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span>.</p><p>You can check <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> <a href=\"//codeforces.com/contest/346/submission/4523388\">'s solution</a> for detail.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/346\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/347\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-4906-8958\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"4906\",\n blogEntryId: \"8903\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+56</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/MinakoKojima\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/MinakoKojima\">\n MinakoKojima\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8903#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8903#comments\">\n 66\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8974\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (56)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146290\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mohammadrdeh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/47/avatar/91eee3f7a5ec41f6.jpg'/> </a>\n <div><a href=\"/profile/mohammadrdeh\" title=\"Specialist mohammadrdeh\" class=\"rated-user user-cyan\">mohammadrdeh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146290\" href=\"?#comment-146290\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146290\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"14\"\r\n data-commentUserId=\"47\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+14</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146290\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>there is a typo: "... the classical <strong>LCA</strong> problem ..." => <strong>LCS</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146290 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146290 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146290\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146291\" commentParentId=\"146290\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146291\" href=\"?#comment-146291\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146290\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146291\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146291\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you. Fixed. m(_ _)m</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146291 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146291 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146291\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146297\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 05:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146297\" href=\"?#comment-146297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Actually our standard solution to C is O(b-a+n). O(b-a+n),O(b-a+nlogn),O((b-a+n)logn) are all able to pass during the test.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146297\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146335\" commentParentId=\"146297\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mmaxio\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/486/avatar/4bb53c24fc9e4c1.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/mmaxio\" title=\"International Master mmaxio\" class=\"rated-user user-orange\">mmaxio</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 17:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146335\" href=\"?#comment-146335\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146297\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146335\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146335\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"486\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146335\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>oh, never mind</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146335 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146335 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146335\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146299\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shashwat.gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6204/avatar/67f8e17c53f70578.jpg'/> </a>\n <div><a href=\"/profile/shashwat.gupta\" title=\"Specialist shashwat.gupta\" class=\"rated-user user-cyan\">shashwat.gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146299\" href=\"?#comment-146299\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146299\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"6204\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146299\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Problem B: Can you Explain little bit more on How "Aho-Corasick automation, or KMP" can help in figuring out smallest string that does not contain virus.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146299 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146299 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146299\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146300\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146300\" href=\"?#comment-146300\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146300\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146300\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For B, I already had the intuitive idea that this problem will be solved by either Aho-Corasick algorithm or KMP with dp, but I could not formalize the idea of states transition in dp. Could you please just provide the state in your dp algorithm?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146300 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146300 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146300\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146354\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146354\" href=\"?#comment-146354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146354\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Original problem can be solved by dp with two parameters DP[Len(s)] [Len(t)]. <a href=\"https://en.wikipedia.org/wiki/Longest_common_subsequence_problem\">http://en.wikipedia.org/wiki/Longest_common_subsequence_problem</a></p><p>To solve B you need to modificate it to DP[Len(s)][Len(t)][Len(virus)-1] where third parameter means maximum length of suffix of LCS that equal to prefix of virus.</p><p>To easy check where we go from K state (third parameter) by character C we can make automat on prefix function by virus.</p><p>Then if we stand in DP[i][j][k] :<br /> 1) if(s[i] == t[j] and Automat[k][c]<Len(virus) we try to relax DP[i+1][j+1][Automat[k][c]]<br /> 2) Try to relax DP[i][j+1][k] and DP[i+1][j][k]</p><p><strong>UPD</strong> My solution: <a href=\"//codeforces.com/contest/346/submission/4532899\">http://codeforces.com/contest/346/submission/4532899</a> (hope it understandable)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146354\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146357\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146357\" href=\"?#comment-146357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>got it, many thanks to you man :) Also understood why KMP tag mentioned in the problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146357\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146493\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lama\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/72190/avatar/735906a91d1576e3.jpg'/> </a>\n <div><a href=\"/profile/lama\" title=\"Expert lama\" class=\"rated-user user-blue\">lama</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 18:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146493\" href=\"?#comment-146493\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146493\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146493\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) Can you please explain what "maximum length of suffix of LCS that equal to prefix of virus" means? 2) What is an automat?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146493 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146493 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146493\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146519\" commentParentId=\"146493\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/25/2013 05:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146519\" href=\"?#comment-146519\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146493\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146519\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146519\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146519\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) We stand in DP[i][j][k]-state (in which we store longest LCS), virus = "virus" <br /> Let's go from k = 0 to 4,then:</p> <pre><code>0) DP[i][j][0] means that finded LCS not ends on "v" or "vi" or "vir" or "viru" or "virus". (example: "a")\n\n1) DP[i][j][1] means that finded LCS ends on "v", but not on "vi" or "vir" or "viru" or "virus". (example: "av")\n\n2) DP[i][j][2] means that finded LCS ends on "vi", but not on "vir" or "viru" or "virus". (example: "avi")\t\n\n3) DP[i][j][3] means that finded LCS ends on "vir", but not on "viru" or "virus". (example: "avir")\n\n4) DP[i][j][4] means that finded LCS ends on "viru", but not on "virus". (example: "aviru")\n\nWe take "longest suffix of LCS that equal prefix of virus", because virus could be: "vvvvv" or "ababv" (and infinite others)\n If LCS = "avvv" - it ends on "v","vv","vvv". (virus = "vvvvv")\n If LCS = "aabab" - it ends on "ab" and "abab". (virus = "ababv")\n</code></pre><p><a href=\"https://en.wikipedia.org/wiki/Knuth%E2%80%93Morris%E2%80%93Pratt_algorithm\">KMP</a></p><p>2) <a href=\"https://en.wikipedia.org/wiki/Automata_theory\">http://en.wikipedia.org/wiki/Automata_theory</a></p><p>Can't find nothing about automaton on prefix-function in english. I hope you will be able understand <a href=\"http://e-maxx.ru/algo/prefix_function\">this</a> with some translator (google translate for example).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146519 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146519 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146519\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"551712\" commentParentId=\"146519\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/srv_twry\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/447741/avatar/d1a80b00eb029c2b.jpg'/> </a>\n <div><a href=\"/profile/srv_twry\" title=\"Expert srv_twry\" class=\"rated-user user-blue\">srv_twry</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/19/2019 12:58\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-551712\" href=\"?#comment-551712\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146519\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"551712\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"447741\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-551712\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Fortunately, the e-maxx article on Prefix function has been translated in English and can be found here: <a href=\"https://cp-algorithms.com/string/prefix-function.html#toc-tgt-12\">prefix-function: automaton on prefix-function</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-551712 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-551712 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-551712\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"768401\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ttbbnnn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1694563/avatar/ff85df0301cf6f76.jpg'/> </a>\n <div><a href=\"/profile/ttbbnnn\" title=\"Master ttbbnnn\" class=\"rated-user user-orange\">ttbbnnn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2021 20:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-768401\" href=\"?#comment-768401\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"768401\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1694563\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-768401\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My solution for B got a WA on test 41 and I don't know why :<, please help me with this code: <a href=\"https://codeforces.com/contest/346/submission/109283664\">https://codeforces.com/contest/346/submission/109283664</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-768401 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-768401 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-768401\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146301\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146301\" href=\"?#comment-146301\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146301\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146301\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146301\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"So the remians work is to delete those same xi, and watch out some situation could cause degeneration. Many of us failed in this last step and got TLE", I really could not understand this. What you you mean by degeneration in this case? Please explain this last important step.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146301 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146301 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146301\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146302\" commentParentId=\"146301\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:37\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146302\" href=\"?#comment-146302\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146301\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146302\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146302\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>suppose b=1, all x[i]>a, what will happen?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146302 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146302 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146302\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146304\" commentParentId=\"146302\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146304\" href=\"?#comment-146304\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146302\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146304\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146304\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As b = 1, All x[i] > a. Then a % x[i] = a. So if we take this, then we will lead to a — a = 0, which is less than b. So we need to move one by one, so answer would be a.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146304 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146304 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146304\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146309\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146309\" href=\"?#comment-146309\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146309\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146309\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Alice and Bob problem how do you prove that you will always get {d, 2d, 3d, ... max{xi}} in the end. It is easy to see but I am unable to prove it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146309 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146309 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146309\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146365\" commentParentId=\"146309\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marat.snowbear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98082/avatar/1499cf6d0c86172.jpg'/> </a>\n <div><a href=\"/profile/marat.snowbear\" title=\"International Master marat.snowbear\" class=\"rated-user user-orange\">marat.snowbear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146365\" href=\"?#comment-146365\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146309\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146365\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"98082\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146365\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I convinced myself like this:</p> <ol> <li>Prove that we will be able to get d by some sequence of subtractions.</li> <li>Prove that we will be able to generate {d, 2d, 3d, ...}</li> <li>Prove that we will not be able to get anything else except for { d, 2d, 3d, ... }</li> </ol><p>In details:</p> <ol> <li><p>See <a href=\"https://en.wikipedia.org/wiki/Euclidean_algorithm\">Euclidean algorithm for finding GCD</a>. If you will look into the description or code you will see that it does exactly what is asked in this problem — subtracts numbers one from another. And the result is GCD of original two numbers. So you can see that by some sequence of subtractions you can get GCD.</p></li> <li><p>If you already have d which GCD of all the numbers then you can easily fill all the gaps in { d, 2d, 3d, ..., max } sequence by starting subtracting d from { max, max — d, max — 2d, ... }. So you will get the intended set.</p></li> <li><p>You cannot subtract two numbers a and b which have GCD(a, b) = d and get result which won't be dividable by d. So if you start with set where every numbers can be divided by d then no matter what you subtract you will always have the result which is also dividable by d.</p></li> </ol></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146365 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146365 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146365\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146390\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 16:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146390\" href=\"?#comment-146390\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146390\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146390\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, got it. Thanks!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146390 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146390 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146390\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"774539\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/25/2021 20:24\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-774539\" href=\"?#comment-774539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"774539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-774539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-774539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-774539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-774539\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146310\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i_coder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i_coder\" title=\"Expert i_coder\" class=\"rated-user user-blue\">i_coder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146310\" href=\"?#comment-146310\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146310\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"41979\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146310\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Is this the final editorial (except the D problem) ? The explanations to problems B and C are very limited and not at all well elaborated.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146310 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146310 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146310\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146314\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146314\" href=\"?#comment-146314\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146314\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146314\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can you tell me that why the number of rounds in Problem A will be max(xi)/d-n ? How do you come to this point ? can you please tell me this as am not to figure out this thing ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146314 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146314 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146314\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146316\" commentParentId=\"146314\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:45\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146316\" href=\"?#comment-146316\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146314\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146316\" revisionCount=\"7\" revision=\"7\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">7</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146316\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146316\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>take example <br /> 3 9 54 <br /> gcd (3, 9, 54) = 3 <br /> Now total rounds possible including (3, 9, 54) =<br />all multiples of 3 upto 54 <br /> 3, 6, 9, 12, 15, 18 ... 54 <br /> </p><p>So total count of these numbers = 54 / 3 = 18. <br /> </p><p>Now as out of these numbers 3 numbers are already taken, so subtract 3 <br /> so rounds remaining = 18 — 3 = 15 </p><p>Now it is very easy to generalize for 3 being d and 54 being n</p><p>answer would be n / d — n. <br /> I hope it is clear now :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146316 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146316 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146316\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146319\" commentParentId=\"146316\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146319\" href=\"?#comment-146319\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146316\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146319\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146319\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes, it is more clear to me now. but one thing is that how did you approach to gcd thing ? I understood the problem, the logic and all. how did you approach that it will be done using gcd thing and all ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146319 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146319 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146319\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146322\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146322\" href=\"?#comment-146322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146322\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My Ideas during solving the problem: <br /> all the examples had gcd 1. So I directly thought answer as max(xi) — n. <br /> But I thought it can not be too simple, I need to think more. <br /> So I took a case 2 4 6, I immediately found I am wrong in this case. <br /> Then the idea came into mind that if gcd of numbers is g. then we can not create any number not divisible by g because (g *k1 — k * k2) = g * (k1 — k2). </p><p>So Finally I coded it and got accpeted :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146322\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146338\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 19:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146338\" href=\"?#comment-146338\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146338\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146338\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>given the numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>, what is the minimum positive value you can achieve by combining them? </p><p>Let's write down the equation: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>·<i>x</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub>·<i>x</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>n</i></sub>·<i>x</i><sub class=\"lower-index\"><i>n</i></sub> = <i>d</i></span>, where <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> are some unknown integers. </p><p>It is, as you can see, none other than linear Diophantine equation. And it is known there is no solutions if <span class=\"tex-span\"><i>d</i></span> is not a multiple of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span> </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146338 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146338 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146338\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146317\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/subway\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123924/avatar/706e86f587cbabf0.jpg'/> </a>\n <div><a href=\"/profile/subway\" title=\"Expert subway\" class=\"rated-user user-blue\">subway</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146317\" href=\"?#comment-146317\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146317\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146317\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@hellodear-the final set will contain all elements {d,2d,3d,..max(Xi)} (d=gcd of all elements) so total no. of elements in final set =max(Xi)/d since initially we have 'n' elements total no. of new elements to be added in set to make it complete=(max(Xi)/d)-n.. hope this helps you..:)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146317 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146317 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146317\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146320\" commentParentId=\"146317\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146320\" href=\"?#comment-146320\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146317\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146320\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146320\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in this thing, I was applying some game theory, but it doesn't include anything like that. when the question says optimally, then how do you form examples so as to test your code on them ? because optimally means in the best they can. can you elaborate ? thanks to you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146320 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146320 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146320\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146324\" commentParentId=\"146320\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146324\" href=\"?#comment-146324\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146320\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146324\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146324\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146324\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>optimality argument is simple and also given in the editorial itself. <br /> As total you numbers finally would be {d, 2 * d,, .,, max (xi)}. <br /> Hence whatever you add to the these set, no other person will be able to add that as he has to add a new number everytime to this test. <br /> So outcome depend on the parity of turns.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146324 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146324 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146324\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146325\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sinamosavi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/87557/avatar/bde58fa97bcc5eb0.jpg'/> </a>\n <div><a href=\"/profile/sinamosavi\" title=\"Pupil sinamosavi\" class=\"rated-user user-green\">sinamosavi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146325\" href=\"?#comment-146325\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146325\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"87557\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146325\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the complete proof for A.Div1 is not that much straightforward. Maybe I'm making it too much difficult, but this is my complete proof:</p><p>First by induction, we prove that the numbers in the end will be <span class=\"tex-span\"><i>a</i>, 2<i>a</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Let <span class=\"tex-span\"><i>g</i> = <i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ... , <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span>. It's trivial that in the end <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>. Assume that <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>, because our numbers will be <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), 2<i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>, so we would have a new gcd. That's a contradiction, so <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) = <i>g</i></span> and our numbers will be <span class=\"tex-span\"><i>g</i>, 2<i>g</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Each move adds one number and in the end there will be <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e6ac12549498d8aaad3d63270d12497bc74a9f84.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> numbers, so the answer wil be the parity of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/48ba1bfd0fa315ab1595947b8e046b4cc211b908.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Sorry for my bad English.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146325 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146325 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146325\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146332\" commentParentId=\"146325\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146332\" href=\"?#comment-146332\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146325\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146332\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-13\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146332\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What about this test <code>2 3 5</code>? <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≠ <i>gcd</i></span></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146332 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146332 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146332\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146333\" commentParentId=\"146332\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146333\" href=\"?#comment-146333\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146332\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146333\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146333\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Oops. You've meant that <span class=\"tex-span\"><i>a</i></span> — is the result. Sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146333 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146333 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146333\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146334\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 16:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146334\" href=\"?#comment-146334\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146334\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146334\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146334\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>But how to prove that there is always a way to choose <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> while the number of the current round less than the maximum number of rounds? (Div2C)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146334 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146334 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146334\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146339\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:22\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146339\" href=\"?#comment-146339\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146339\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146339\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146339\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If gcd{xi}＝1, then for every xi there must exist ti to make sum｛xi*ti｝＝1. </p><p>(For example, x1＝5,x2＝7,then t1＝3,t2＝-2.x1*t1＋x2*t2＝1.)</p><p>And sum{xi*ti} can be performed in a few turns. ( (5-(7-5))-(7-5). )</p><p>And if we can get 1, then what number between [1,max{xi}] can't we get？</p><p>if gcd{xi}≠1.the proof is similar.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146339 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146339 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146339\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146341\" commentParentId=\"146339\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146341\" href=\"?#comment-146341\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146339\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146341\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146341\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why there is must exist such t[i]?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146341 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146341 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146341\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146366\" commentParentId=\"146341\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146366\" href=\"?#comment-146366\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146341\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146366\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146366\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You must know if gcd(a,b)＝1, there must exist x and y to make ax＋by＝1. It can be proved from this.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146366 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146366 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146366\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146376\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146376\" href=\"?#comment-146376\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146376\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146376\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146376\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So.. If we divide all the numbers by GCD, and after that a pair of coprime numbers have appeared, we always can reach 1. Let's choose coprime <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, then <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> will be also coprime with <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, and it will be less then <span class=\"tex-span\"><i>max</i>(<i>x</i>, <i>y</i>)</span>. So we can choose <span class=\"tex-span\"><i>mid</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>x</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>min</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>y</i><sub class=\"lower-index\">1</sub></span>, and they are coprime, and <span class=\"tex-span\">|<i>x</i><sub class=\"lower-index\">1</sub> - <i>y</i><sub class=\"lower-index\">1</sub>|</span> will be less than <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>. And etc. by induction. But what to do if there is not a pair of coprime numbers after dividing by GCD? For example <code>35 45 63</code>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146376 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146376 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146376\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146404\" commentParentId=\"146376\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146404\" href=\"?#comment-146404\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146376\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146404\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146404\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146404\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>63*2＋45*5＋35*(-10)＝1</p><p>Because gcd (35,45)＝5, we can consider 35 and 45 as one number 5x. Because gcd(5,63)＝1, so there must exist x,y to make 5x＋63y＝1.</p><p>So here comes a tragedy. We can get 5 first. Then we use this number together with 63 to make 1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146404 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146404 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146404\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146346\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KiAsaGibona\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/KiAsaGibona\" title=\"Specialist KiAsaGibona\" class=\"rated-user user-cyan\">KiAsaGibona</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 21:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146346\" href=\"?#comment-146346\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146346\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146346\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"99053\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146346\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Someone please explain the greedy idea of (Div 1 C) (Number Transformation II). Thanks in advance :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146346 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146346 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146346\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146367\" commentParentId=\"146346\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 09:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146367\" href=\"?#comment-146367\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146346\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146367\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146367\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's a pretty simple greedy idea: Just pick the <code>x</code> that makes the value of <code>a</code> smallest after applying the operation <code>a = a - a%x</code> (or subtract 1 if no choice for <code>x</code> makes <code>a</code> smaller). The proof why this works is given in the editorial: it is never better to get a larger number, so you should get the smallest one you can.</p><p>As listed on the last paragraph of the editorial you have to be careful to remove all <code>x</code> that are either duplicates or cannot be used anymore (<code>a - (a%x)</code> is smaller than <code>b</code>), otherwise you will get TLE.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146367 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146367 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146367\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146382\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146382\" href=\"?#comment-146382\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146382\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146382\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146382\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>how to find this x for each number?</p><p>we will iterate on all x[i]s and only delete x[i]s when x[i] > a?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146382 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146382 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146382\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146405\" commentParentId=\"146382\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146405\" href=\"?#comment-146405\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146382\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146405\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146405\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Iterate through all x[i]s and delete them when a — (a%x[i]) is smaller than b (if you only delete when x[i] > a, you will also get TLE).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146405 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146405 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146405\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146625\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 17:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146625\" href=\"?#comment-146625\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146625\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146625\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm really striving to understand why the algorithm turns out to be linear instead of quadratic... I know the editorial says "That is because, we could cut exactly <span class=\"tex-span\"><i>max</i>{<i>xi</i>}</span> in each 2 step.", but I can't really get what it means :\\</p><p>Can you give me a hint? Thanks :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146625 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146625 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146625\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146643\" commentParentId=\"146625\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/xenoslash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88090/avatar/f75f8cbc20d6133f.jpg'/> </a>\n <div><a href=\"/profile/xenoslash\" title=\"Expert xenoslash\" class=\"rated-user user-blue\">xenoslash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 19:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146643\" href=\"?#comment-146643\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146625\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146643\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146643\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"88090\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146643\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have an easy intuition of cutting at least max{xi} in O(1) steps, not sure what was the intended 2 step proofs though. I am going to use xi to refer to max{xi}, and assume that proper care is taken to only keep the relevant xi's.</p><p>When we do a-(a % xi), we bring caused a to be the next largest integer <= a that is a multiple of xi, since now new_a % xi = 0. Then, if a is divisible by xi, you can do.., do a-1 (causing it to be non-divisible by xi), then finally a-(a%xi) again. In this 3 step sequence you have brought a down to the next lower multiple of xi, and have essentially cut max{xi} in O(1) number of steps.</p><p>Sample code : <a href=\"//codeforces.com/contest/346/submission/4545367\">http://codeforces.com/contest/346/submission/4545367</a> Yeah I used tree set so it's not exactly O(n).. but hash set keeps giving me TLE :(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146643 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146643 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146643\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146689\" commentParentId=\"146643\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2013 12:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146689\" href=\"?#comment-146689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146643\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you very much, that was really eye-opening! This is why I love Codeforces, great community! :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146689\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146371\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Corvo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/11909/avatar/8404ac1aff5270ec.jpg'/> </a>\n <div><a href=\"/profile/Corvo\" title=\"Pupil Corvo\" class=\"rated-user user-green\">Corvo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 12:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146371\" href=\"?#comment-146371\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146371\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"11909\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146371\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please explain why the problem is solved through the GDC (A)? I tried like <a href=\"https://codeforces.com/contest/347/submission/4535232\">this</a>, but I still can not understand why you can not do. Please give a short test on which the decision falls. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146371 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146371 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146371\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146375\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146375\" href=\"?#comment-146375\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146375\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146375\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><pre><code>3\n14 4 2\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146375 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146375 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146375\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146378\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akashdeep\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/39866/avatar/6f66d1bbe26ef4ca.jpg'/> </a>\n <div><a href=\"/profile/akashdeep\" title=\"International Master akashdeep\" class=\"rated-user user-orange\">akashdeep</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146378\" href=\"?#comment-146378\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146378\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"39866\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146378\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Because only those numbers are possible in the game which are multiple of gcd. See this simplest test case</p> <pre><code>2\n4 6\n</code></pre><p>The only number possible in the game is (6-4) i.e. 2, but in your code u are assuming that somehow these (1,2,3,5) numbers can be obtained which is a wrong assumption.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146378 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146378 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146378\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146408\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/NegaTeeF\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/NegaTeeF\" title=\"Master NegaTeeF\" class=\"rated-user user-orange\">NegaTeeF</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 20:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146408\" href=\"?#comment-146408\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146408\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"65829\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146408\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Explain please, how to do Div1-D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146408 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146408 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146408\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146410\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/irakli_p\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29034/avatar/d879a3156498c6c7.jpg'/> </a>\n <div><a href=\"/profile/irakli_p\" title=\"Expert irakli_p\" class=\"rated-user user-blue\">irakli_p</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 21:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146410\" href=\"?#comment-146410\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146410\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29034\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146410\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i didn't understand Div 2 — D can someone explain it to me please </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146410 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146410 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146410\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146443\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/suiyuan2009\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49923/avatar/9065a92c0b30b883.jpg'/> </a>\n <div><a href=\"/profile/suiyuan2009\" title=\"Master suiyuan2009\" class=\"rated-user user-orange\">suiyuan2009</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 13:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146443\" href=\"?#comment-146443\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146443\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49923\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146443\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>problem B,ac automachine is doing the thing that belong to kmp</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146443 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146443 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146443\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146452\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 17:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146452\" href=\"?#comment-146452\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146452\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146452\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div1_E: Should the "Doodler" jump over the platform which H = P ? I just confused about that.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146452 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146452 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146452\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146480\" commentParentId=\"146452\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 11:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146480\" href=\"?#comment-146480\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146452\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146480\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146480\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OK I got the answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146480 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146480 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146480\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146463\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146463\" href=\"?#comment-146463\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146463\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"44\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+44</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146463\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>still waiting for D tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146463 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146463 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146463\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147566\" commentParentId=\"146463\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/05/2013 05:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147566\" href=\"?#comment-147566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146463\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>.. Update .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147566\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"235917\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/saurabhverma\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/143428/avatar/48808a8d5db775d4.jpg'/> </a>\n <div><a href=\"/profile/saurabhverma\" title=\"Expert saurabhverma\" class=\"rated-user user-blue\">saurabhverma</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2015 20:05\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-235917\" href=\"?#comment-235917\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"235917\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"143428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-235917\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In my approach to problem div1 B, I calculated longest common subsequence, prepended virus to it, calculated the Z function and deleted every character which had z[i] >= virus.size(). I don't think my approach is wrong. Can someone tell me if my code is wrong or the approach has some flaw. Thanks. Submission : <a href=\"//codeforces.com/contest/346/submission/11491420\">http://codeforces.com/contest/346/submission/11491420</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-235917 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-235917 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-235917\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"530287\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arpit4427\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/717924/avatar/90dcbc94a1e57cf.jpg'/> </a>\n <div><a href=\"/profile/arpit4427\" title=\"Expert arpit4427\" class=\"rated-user user-blue\">arpit4427</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/26/2019 14:04\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-530287\" href=\"?#comment-530287\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"530287\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"530287\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"717924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-530287\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone explain how to solve this problem <a href=\"/contest/346/problem/B\" title=\"Codeforces Round 201 (Div. 1)\">346B - Lucky Common Subsequence</a>? I have went thorugh the editorial but I could not understand.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-530287 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-530287 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-530287\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8974\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8974 = true;\r\nvar lastPreviewContent8974 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8974] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8974] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:24</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812874998e81759f',t:'MTY5NjcwNTk0NS4wMjkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1752,"cells":{"problem_id":{"kind":"string","value":"347A"},"contest":{"kind":"string","value":"347"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Difference Row"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Difference Row</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You want to arrange <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> in some order in a row. Let's define the value of an arrangement as the sum of differences between all pairs of adjacent integers.</p><p>More formally, let's denote some arrangement as a sequence of integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span>, where sequence <span class=\"tex-span\"><i>x</i></span> is a permutation of sequence <span class=\"tex-span\"><i>a</i></span>. The value of such an arrangement is <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">1</sub> - <i>x</i><sub class=\"lower-index\">2</sub>) + (<i>x</i><sub class=\"lower-index\">2</sub> - <i>x</i><sub class=\"lower-index\">3</sub>) + ... + (<i>x</i><sub class=\"lower-index\"><i>n</i> - 1</sub> - <i>x</i><sub class=\"lower-index\"><i>n</i></sub>)</span>.</p><p>Find the largest possible value of an arrangement. Then, output the lexicographically smallest sequence <span class=\"tex-span\"><i>x</i></span> that corresponds to an arrangement of the largest possible value.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 100</span>). The second line contains <span class=\"tex-span\"><i>n</i></span> space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">|<i>a</i><sub class=\"lower-index\"><i>i</i></sub>| ≤ 1000</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print the required sequence <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span>. Sequence <span class=\"tex-span\"><i>x</i></span> should be the lexicographically smallest permutation of <span class=\"tex-span\"><i>a</i></span> that corresponds to an arrangement of the largest possible value.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>100 -100 50 0 -50<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>100 -50 0 50 -100 <br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the sample test case, the value of the output arrangement is <span class=\"tex-span\">(100 - ( - 50)) + (( - 50) - 0) + (0 - 50) + (50 - ( - 100)) = 200</span>. No other arrangement has a larger value, and among all arrangements with the value of <span class=\"tex-span\">200</span>, the output arrangement is the lexicographically smallest one.</p><p>Sequence <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ... , <i>x</i><sub class=\"lower-index\"><i>p</i></sub></span> is <span class=\"tex-font-style-it\">lexicographically smaller</span> than sequence <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">2</sub>, ... , <i>y</i><sub class=\"lower-index\"><i>p</i></sub></span> if there exists an integer <span class=\"tex-span\"><i>r</i></span> <span class=\"tex-span\">(0 ≤ <i>r</i> < <i>p</i>)</span> such that <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub> = <i>y</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub> = <i>y</i><sub class=\"lower-index\">2</sub>, ... , <i>x</i><sub class=\"lower-index\"><i>r</i></sub> = <i>y</i><sub class=\"lower-index\"><i>r</i></sub></span> and <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>r</i> + 1</sub> < <i>y</i><sub class=\"lower-index\"><i>r</i> + 1</sub></span>.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"a84fc0256a4dde690f718380177c3915\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"f8f8f6cf474a1d90f03554b971b57bc6697e07dd\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='a84fc0256a4dde690f718380177c3915'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F347%2Fproblem%2FA%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='a84fc0256a4dde690f718380177c3915'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/347\">Codeforces Round 201 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='a84fc0256a4dde690f718380177c3915'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/347/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Constructive algorithms\">\r\n constructive algorithms\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Sortings, orderings\">\r\n sortings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1300\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='a84fc0256a4dde690f718380177c3915'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3508\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='a84fc0256a4dde690f718380177c3915'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3508\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8896\" title=\"Codeforces Round #201\" target=\"_blank\">Codeforces Round #201</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1862:1863\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8903\" title=\"Codeforces Round #201 Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1865\" resourceName=\"Codeforces Round #201 Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/347\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/347/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/347/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/347/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/347/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/347/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/347/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/347/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_4e905f6472fe78c6cf7d91c0012ef3a9d4ccb349\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Difference Row</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You want to arrange <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> in some order in a row. Let's define the value of an arrangement as the sum of differences between all pairs of adjacent integers.</p><p>More formally, let's denote some arrangement as a sequence of integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span>, where sequence <span class=\"tex-span\"><i>x</i></span> is a permutation of sequence <span class=\"tex-span\"><i>a</i></span>. The value of such an arrangement is <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">1</sub> - <i>x</i><sub class=\"lower-index\">2</sub>) + (<i>x</i><sub class=\"lower-index\">2</sub> - <i>x</i><sub class=\"lower-index\">3</sub>) + ... + (<i>x</i><sub class=\"lower-index\"><i>n</i> - 1</sub> - <i>x</i><sub class=\"lower-index\"><i>n</i></sub>)</span>.</p><p>Find the largest possible value of an arrangement. Then, output the lexicographically smallest sequence <span class=\"tex-span\"><i>x</i></span> that corresponds to an arrangement of the largest possible value.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 100</span>). The second line contains <span class=\"tex-span\"><i>n</i></span> space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">|<i>a</i><sub class=\"lower-index\"><i>i</i></sub>| ≤ 1000</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print the required sequence <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span>. Sequence <span class=\"tex-span\"><i>x</i></span> should be the lexicographically smallest permutation of <span class=\"tex-span\"><i>a</i></span> that corresponds to an arrangement of the largest possible value.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />100 -100 50 0 -50<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>100 -50 0 50 -100 <br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the sample test case, the value of the output arrangement is <span class=\"tex-span\">(100 - ( - 50)) + (( - 50) - 0) + (0 - 50) + (50 - ( - 100)) = 200</span>. No other arrangement has a larger value, and among all arrangements with the value of <span class=\"tex-span\">200</span>, the output arrangement is the lexicographically smallest one.</p><p>Sequence <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ... , <i>x</i><sub class=\"lower-index\"><i>p</i></sub></span> is <span class=\"tex-font-style-it\">lexicographically smaller</span> than sequence <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">2</sub>, ... , <i>y</i><sub class=\"lower-index\"><i>p</i></sub></span> if there exists an integer <span class=\"tex-span\"><i>r</i></span> <span class=\"tex-span\">(0 ≤ <i>r</i> < <i>p</i>)</span> such that <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub> = <i>y</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub> = <i>y</i><sub class=\"lower-index\">2</sub>, ... , <i>x</i><sub class=\"lower-index\"><i>r</i></sub> = <i>y</i><sub class=\"lower-index\"><i>r</i></sub></span> and <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>r</i> + 1</sub> < <i>y</i><sub class=\"lower-index\"><i>r</i> + 1</sub></span>.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:53</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bdec2de85aae',t:'MTY5NjY0NjAzMy41MTEwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Constructive algorithms\", \"Implementation problems, programming technics, simulation\", \"Sortings, orderings\"]"},"short_tags":{"kind":"string","value":"[\"constructive algorithms\", \"implementation\", \"sortings\", \"*1300\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8903"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"1c88316eb9ff5851524d80ea59ef3f32\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #201 Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #201 Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='1c88316eb9ff5851524d80ea59ef3f32'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8903\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/MinakoKojima\">MinakoKojima</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/MinakoKojima\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/MinakoKojima\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/MinakoKojima\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/MinakoKojima\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/MinakoKojima\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/MinakoKojima\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/MinakoKojima\" style=\"text-decoration:none;color:black !important;\">MinakoKojima's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8958\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8903\"> <p>Codeforces Round #201 Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a>,\r\n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><img alt=\" \" src=\"/predownloaded/41/3f/413f7303374a112dddc1e63e29cfc12924514cd7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><h1>Overview</h1><p>In DIV 1, there are 4 interesting problems together with a normal one. We think it is reasonable because we can't have a round fullly with intelligence. Problem A, C have weak pretests while others intended to be strong. About more then 200 participants solve A in the early 45mins, then a few of them start from C while most of the other start from B. </p><p>Problem B is a rather standard problem, but if you're unfamiliar with the algorithm, it can be very hard. Problem C is a more intersting problem. As the name implies, there was <a href=\"//codeforces.com/problemset/problem/251/C\">a similar version</a> in the previous round before, but this time it has a brand new constrains.(So here we have a psychology experiment: could different constrains make people thinking in a slightly different way?ww)</p><p>The standard solution of problem C is <span class=\"tex-span\"><i>O</i>((<i>b</i> - <i>a</i>) + <i>nlogn</i>)</span>. The first expected correct solution was written by <a class=\"rated-user user-orange\" href=\"/profile/zeliboba\" title=\"International Master zeliboba\">zeliboba</a>. <a href=\"//codeforces.com/contest/346/submission/4512654\">http://codeforces.com/contest/346/submission/4512654</a></p><p>After that, some people start to solve problem D. Problem D looks like a hard dp problem on a graph at the first glance, the key point is how to avoid the circle in the transfer equation. It turn out to be elegant after you could found a right order of the evaluation. Problem E is challenging which you need find a way to transform the original question into a smaller scale, and cut off many many corner cases ... And in the very end, you find a way like binary search to get <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span> as the time complexity. No one manage to solve problem E during the contest, maybe <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> is the man who closest to it.</p><p>The winner comes to <a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"Grandmaster cgy4ever\">cgy4ever</a>, because he found the draw-black in his previous C submission during the very beginning even when there is nobody hack him! He resubmit it decisively and get back when finished problem D. After that, he use the same trick which made him failed before to hack others and got a handsomely rewards. The second place went to <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a>, because of the combination of decent speed in A, B, C, D.</p><p>Problem B belongs to me, problem C belongs to <a class=\"rated-user user-violet\" href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\">CMHJT</a> and others belong to <a class=\"rated-user user-orange\" href=\"/profile/UESTC_Nocturne\" title=\"International Master UESTC_Nocturne\">UESTC_Nocturne</a>. The illustrator of problem C is <a href=\"http://www.pixiv.net/member_illust.php?mode=medium&illust_id=38602657\">Chairman Miao(貓主席)</a>.</p><h1>Editorial</h1><h3><a href=\"//codeforces.com/problemset/problem/346/A\">Problem A. Alice and Bob</a></h3><h4>Brief description:</h4><p>Alice and Bob play a game, the rules are as follows: First, they will get a set of <span class=\"tex-span\"><i>n</i></span> distinct numbers. And then they take turns to do the following operations. During each operation, either Alice or Bob can choose two different numbers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> from the set, as long as <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> is not in the set, then they add it to the set. The person who can not choose two numbers successfully will lose the game. The question is who will finally win the game if both of them do operations optimally. Remember that Alice always goes first.</p><h4>Analysis:</h4><p>First, no matter what happend, the number set we get at the very endding will be same all the time. Let's say <span class=\"tex-span\"><i>d</i> = <i>gcd</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}. Then the set in the endding will be some things like {<span class=\"tex-span\"><i>d</i></span>, <span class=\"tex-span\">2<i>d</i></span>, <span class=\"tex-span\">3<i>d</i></span>, ... <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}}. So there is always <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub>} / <i>d</i></span> — <span class=\"tex-span\"><i>n</i></span> rounds. And what we should do rest is to check the parity of this value.</p><h3><a href=\"//codeforces.com/problemset/problem/346/B\">Problem B. Lucky Common Subsequence</a></h3><h4>Brief description:</h4><p>You have been given two strings <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and <span class=\"tex-span\"><i>virus</i></span>, and you have to find the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> without <span class=\"tex-span\"><i>virus</i></span> as a substring.</p><h4>Analysis:</h4><p>This is a rather classical problem, let's say if there is no virus, then it is the classical **LCS ** problem. You can solve this by a <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> dynamic programing.</p><p>When consider about the virus, we should add 1 more dimension on the state to trace the growth of the virus. It can be done by wheather <strong>Aho-Corasick automation</strong>, or <strong>KMP</strong> when there is only one virus in this case. The overall time complexity is <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">3</sup>)</span>.</p><h3><a href=\"//codeforces.com/problemset/problem/346/C\">Problem C. Number Transformation II</a></h3><h4>Brief description:</h4><p>You have a number <span class=\"tex-span\"><i>b</i></span>, and want to minus it to <span class=\"tex-span\"><i>a</i></span>, what you can do in each step is weather subtract 1 or <span class=\"tex-span\"><i>b</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> from <span class=\"tex-span\"><i>b</i></span>. And we ask what is the minimum number of steps you need.</p><h4>Analysis:</h4><p>I bet there is a few people know the greedy method even if he/she have solved the early version before.</p><p><a href=\"//codeforces.com/problemset/problem/251/C\">Codeforces #153 Div 1. Problem C. Number Transformation</a></p><p>Let dp[k] denotes the minimum number of steps to transform b+k to b. In each step, you could only choose i which makes b+k-(b+k) mod x[i] minimal to calc dp[k]. It works bacause dp[0..k-1] is a monotone increasing function. Proof: - Say dp[k]=dp[k-t]+1.If t==1, then dp[0..k] is monotone increasing obviously.Otherwise dp[k-1]<=dp[k-t]+1=dp[k] (there must exist a x[i] makes b+k-1 also transform to b+k-t,and it is not necessarily the optimal decision of dp[k-1]). So dp[k] is a monotone increasing function, we can greedily calc dp[a-b].</p><p>In the first glance, it looks like something which will run in square complexity. But actually is linear. That is because, we could cut exactly max{<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>} in each 2 step. It can be proof by induction.</p><p>So the remians work is to delete those same <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>, and watch out some situation could cause degeneration. Many of us failed in this last step and got <strong>TLE</strong></p><h3><a href=\"//codeforces.com/problemset/problem/346/D\">Problem D. Robot Control</a></h3><p>Let's dp from t to s.</p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>Here dp[u] means, the minimum number of orders mzry1992 needs to send in the worst case. The left-hand-side is sending order while the right-hand side is not. At the beginning, we have dp[t] = 1, and dp[s] will be the answer.</p><p>We can see there is circular dependence in this equation, in this situation, one standard method is using Bellman-Ford algorithm to evaluate the dp function.</p><p>But it is not appropriate for this problem.</p><p>(In fact, we add a part of targeted datas in pretest, these datas are enough to block most of our <a href=\"https://en.wikipedia.org/wiki/Bellman%E2%80%93Ford_algorithm\">Bellman-Ford algorithm</a>, although there is still a few participator can get accepted by Bellman-Ford algorithm during the contest.</p><p>Check <a class=\"rated-user user-violet\" href=\"/profile/rares.buhai\" title=\"Candidate Master rares.buhai\">rares.buhai</a>'s <a href=\"//codeforces.com/contest/346/submission/4520171\">solution</a></p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>The expected solution is evaluating the dp function as the increased value of dp[u] itself. Further analysis shows, wheather we decided sending order or not in u can be judged as the out-degree of u.</p> <pre><code><br />while (!Q.empty()) {\n u = Q.front(), Q.pop_front()\n for each edge from v to u\n --out_degree[v]\n\tif (out_degree[v] == 0) {\n relax dp[v] by dp[u]\n if success, add v to the front of Q\n\t}\n\telse{\n\t relax dp[v] by dp[u] + 1\n\t if success, add v to the back of Q\n }\t\n }\n</code></pre><p>Check <a class=\"rated-user user-orange\" href=\"/profile/Ra16bit\" title=\"International Master Ra16bit\">Ra16bit</a>'s <a href=\"//codeforces.com/contest/346/submission/4519668\">solution</a> to see how it works.</p><h3><a href=\"//codeforces.com/problemset/problem/346/E\">Problem E. Doodle Jump</a></h3><h4>Brief description:</h4><p>You have been give <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>, <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>h</i></span> (gcd(<span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>) = 1), For each <span class=\"tex-span\"><i>ai</i></span> mod <span class=\"tex-span\"><i>p</i></span>, (<span class=\"tex-span\"><i>i</i></span>∈[1, n]), check weather the maximum distance in neighborhood after sorting is <= <span class=\"tex-span\"><i>h</i></span>. </p><h4>Analysis:</h4><p>Take <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 for example ... Divided the numbers in group.</p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 18\n</code></pre><p>We start a new group when the number > P</p><p>We found the difference between the elements of the first group is 5, The subsequent is filling some gap between the them ...</p><p>After some observation we could found that we should only consider into one gap ...(e.g. [0, 5] or [15, 20] or [20, 25] ... ) </p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>That says .. <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 is roughly equal to some things in small scale?</p><p>So let's check it in detail. Lemma 1. In any case, the gap after 20 won't better than any gap before it.</p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>For example, in this case, the gap after 20 is: 20, 22 And it has 16 in [15, 17] but no 21. </p><p>Is there any chance that [20, 23] is better than [15, 20]?</p><p>No, that is because, when there is no 21, then (19+5)%23 = 1, go to next floor. and there is no corresponding gap after 20 ([22, 24]) for this gap ([17, 19])</p><p>So we only need to consider [15, 20] ... and we found [15, 20] is roughly equal to [0, 5]</p> <pre><code>e.g. : 15 20 17 19 16 18 \nequal: 0 5 2 4 1 3\n</code></pre><p>we say 'roughly' because we havn't check some boundary case like there is 3 but on 18 ... </p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 \n</code></pre><p>If it happend, we should remove the number 3. .. If we can remove the element 5, then we can from a=5, p=23 to a'=2, p'=5 ...(n' = an/p, a' = a-p%a, if there is 3 but no 18, n'=n'-1)</p><p>The rest things is to discuss wheather 5 is necessary or not.</p><p>Let's we have:</p> <pre><code>0 2 4\n1 3\n</code></pre><p>If the 2*n'<5, then there is only one floor, the answer is max(2, 5-2*n'). If there is more than one floor, we could conclude that 5 is useless.</p><p>Proof: Elemets in 1st floor is: </p> <pre><code>0 a 2a 3a ...\n</code></pre><p>Let's say the maximum elements in 1st floor is x, then the minimum element in the 2nd floor is b0 = x+a-p, because b0 — a = x-p, so the difference between b0 and a is equal to the difference between x and p. That is, we can consider [b0, a] rather than [x, p], when there is a element insert in [b0, a], there must be some element insert in [x, p] in the same position.</p><p>So we have have succeeded to transform our original problem into a small one. Of couse, this problem havn't been solved, we haven't consider the time complexity. Says a' = a — p%a, when p = a+1, then a' = a-1, but we have <span class=\"tex-span\"><i>a</i></span> equal to 10^9, it won't work.</p><p>But, let's we have A1, A2, ... An ... and we subtract <span class=\"tex-span\"><i>d</i></span> from all of them, the answer won't be changed. So we can use p%a substitute for a-p%a, this is equivalent to we subtract %p% from all of them ...</p><p>So we set a' = min(a-p%a, p%a), so a'<=a/2, therefore, the final time complexity is <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span>.</p><p>You can check <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> <a href=\"//codeforces.com/contest/346/submission/4523388\">'s solution</a> for detail.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/346\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/347\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-4906-8958\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"4906\",\n blogEntryId: \"8903\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+56</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/MinakoKojima\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/MinakoKojima\">\n MinakoKojima\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8903#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8903#comments\">\n 66\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8974\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (56)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146290\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mohammadrdeh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/47/avatar/91eee3f7a5ec41f6.jpg'/> </a>\n <div><a href=\"/profile/mohammadrdeh\" title=\"Specialist mohammadrdeh\" class=\"rated-user user-cyan\">mohammadrdeh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146290\" href=\"?#comment-146290\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146290\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"14\"\r\n data-commentUserId=\"47\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+14</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146290\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>there is a typo: "... the classical <strong>LCA</strong> problem ..." => <strong>LCS</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146290 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146290 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146290\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146291\" commentParentId=\"146290\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146291\" href=\"?#comment-146291\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146290\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146291\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146291\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you. Fixed. m(_ _)m</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146291 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146291 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146291\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146297\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 05:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146297\" href=\"?#comment-146297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Actually our standard solution to C is O(b-a+n). O(b-a+n),O(b-a+nlogn),O((b-a+n)logn) are all able to pass during the test.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146297\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146335\" commentParentId=\"146297\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mmaxio\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/486/avatar/4bb53c24fc9e4c1.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/mmaxio\" title=\"International Master mmaxio\" class=\"rated-user user-orange\">mmaxio</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 17:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146335\" href=\"?#comment-146335\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146297\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146335\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146335\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"486\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146335\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>oh, never mind</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146335 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146335 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146335\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146299\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shashwat.gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6204/avatar/67f8e17c53f70578.jpg'/> </a>\n <div><a href=\"/profile/shashwat.gupta\" title=\"Specialist shashwat.gupta\" class=\"rated-user user-cyan\">shashwat.gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146299\" href=\"?#comment-146299\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146299\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"6204\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146299\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Problem B: Can you Explain little bit more on How "Aho-Corasick automation, or KMP" can help in figuring out smallest string that does not contain virus.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146299 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146299 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146299\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146300\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146300\" href=\"?#comment-146300\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146300\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146300\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For B, I already had the intuitive idea that this problem will be solved by either Aho-Corasick algorithm or KMP with dp, but I could not formalize the idea of states transition in dp. Could you please just provide the state in your dp algorithm?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146300 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146300 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146300\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146354\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146354\" href=\"?#comment-146354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146354\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Original problem can be solved by dp with two parameters DP[Len(s)] [Len(t)]. <a href=\"https://en.wikipedia.org/wiki/Longest_common_subsequence_problem\">http://en.wikipedia.org/wiki/Longest_common_subsequence_problem</a></p><p>To solve B you need to modificate it to DP[Len(s)][Len(t)][Len(virus)-1] where third parameter means maximum length of suffix of LCS that equal to prefix of virus.</p><p>To easy check where we go from K state (third parameter) by character C we can make automat on prefix function by virus.</p><p>Then if we stand in DP[i][j][k] :<br /> 1) if(s[i] == t[j] and Automat[k][c]<Len(virus) we try to relax DP[i+1][j+1][Automat[k][c]]<br /> 2) Try to relax DP[i][j+1][k] and DP[i+1][j][k]</p><p><strong>UPD</strong> My solution: <a href=\"//codeforces.com/contest/346/submission/4532899\">http://codeforces.com/contest/346/submission/4532899</a> (hope it understandable)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146354\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146357\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146357\" href=\"?#comment-146357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>got it, many thanks to you man :) Also understood why KMP tag mentioned in the problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146357\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146493\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lama\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/72190/avatar/735906a91d1576e3.jpg'/> </a>\n <div><a href=\"/profile/lama\" title=\"Expert lama\" class=\"rated-user user-blue\">lama</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 18:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146493\" href=\"?#comment-146493\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146493\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146493\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) Can you please explain what "maximum length of suffix of LCS that equal to prefix of virus" means? 2) What is an automat?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146493 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146493 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146493\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146519\" commentParentId=\"146493\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/25/2013 05:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146519\" href=\"?#comment-146519\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146493\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146519\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146519\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146519\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) We stand in DP[i][j][k]-state (in which we store longest LCS), virus = "virus" <br /> Let's go from k = 0 to 4,then:</p> <pre><code>0) DP[i][j][0] means that finded LCS not ends on "v" or "vi" or "vir" or "viru" or "virus". (example: "a")\n\n1) DP[i][j][1] means that finded LCS ends on "v", but not on "vi" or "vir" or "viru" or "virus". (example: "av")\n\n2) DP[i][j][2] means that finded LCS ends on "vi", but not on "vir" or "viru" or "virus". (example: "avi")\t\n\n3) DP[i][j][3] means that finded LCS ends on "vir", but not on "viru" or "virus". (example: "avir")\n\n4) DP[i][j][4] means that finded LCS ends on "viru", but not on "virus". (example: "aviru")\n\nWe take "longest suffix of LCS that equal prefix of virus", because virus could be: "vvvvv" or "ababv" (and infinite others)\n If LCS = "avvv" - it ends on "v","vv","vvv". (virus = "vvvvv")\n If LCS = "aabab" - it ends on "ab" and "abab". (virus = "ababv")\n</code></pre><p><a href=\"https://en.wikipedia.org/wiki/Knuth%E2%80%93Morris%E2%80%93Pratt_algorithm\">KMP</a></p><p>2) <a href=\"https://en.wikipedia.org/wiki/Automata_theory\">http://en.wikipedia.org/wiki/Automata_theory</a></p><p>Can't find nothing about automaton on prefix-function in english. I hope you will be able understand <a href=\"http://e-maxx.ru/algo/prefix_function\">this</a> with some translator (google translate for example).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146519 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146519 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146519\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"551712\" commentParentId=\"146519\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/srv_twry\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/447741/avatar/d1a80b00eb029c2b.jpg'/> </a>\n <div><a href=\"/profile/srv_twry\" title=\"Expert srv_twry\" class=\"rated-user user-blue\">srv_twry</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/19/2019 12:58\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-551712\" href=\"?#comment-551712\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146519\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"551712\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"447741\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-551712\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Fortunately, the e-maxx article on Prefix function has been translated in English and can be found here: <a href=\"https://cp-algorithms.com/string/prefix-function.html#toc-tgt-12\">prefix-function: automaton on prefix-function</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-551712 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-551712 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-551712\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"768401\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ttbbnnn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1694563/avatar/ff85df0301cf6f76.jpg'/> </a>\n <div><a href=\"/profile/ttbbnnn\" title=\"Master ttbbnnn\" class=\"rated-user user-orange\">ttbbnnn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2021 20:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-768401\" href=\"?#comment-768401\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"768401\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1694563\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-768401\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My solution for B got a WA on test 41 and I don't know why :<, please help me with this code: <a href=\"https://codeforces.com/contest/346/submission/109283664\">https://codeforces.com/contest/346/submission/109283664</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-768401 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-768401 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-768401\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146301\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146301\" href=\"?#comment-146301\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146301\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146301\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146301\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"So the remians work is to delete those same xi, and watch out some situation could cause degeneration. Many of us failed in this last step and got TLE", I really could not understand this. What you you mean by degeneration in this case? Please explain this last important step.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146301 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146301 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146301\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146302\" commentParentId=\"146301\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:37\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146302\" href=\"?#comment-146302\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146301\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146302\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146302\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>suppose b=1, all x[i]>a, what will happen?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146302 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146302 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146302\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146304\" commentParentId=\"146302\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146304\" href=\"?#comment-146304\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146302\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146304\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146304\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As b = 1, All x[i] > a. Then a % x[i] = a. So if we take this, then we will lead to a — a = 0, which is less than b. So we need to move one by one, so answer would be a.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146304 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146304 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146304\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146309\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146309\" href=\"?#comment-146309\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146309\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146309\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Alice and Bob problem how do you prove that you will always get {d, 2d, 3d, ... max{xi}} in the end. It is easy to see but I am unable to prove it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146309 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146309 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146309\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146365\" commentParentId=\"146309\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marat.snowbear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98082/avatar/1499cf6d0c86172.jpg'/> </a>\n <div><a href=\"/profile/marat.snowbear\" title=\"International Master marat.snowbear\" class=\"rated-user user-orange\">marat.snowbear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146365\" href=\"?#comment-146365\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146309\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146365\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"98082\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146365\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I convinced myself like this:</p> <ol> <li>Prove that we will be able to get d by some sequence of subtractions.</li> <li>Prove that we will be able to generate {d, 2d, 3d, ...}</li> <li>Prove that we will not be able to get anything else except for { d, 2d, 3d, ... }</li> </ol><p>In details:</p> <ol> <li><p>See <a href=\"https://en.wikipedia.org/wiki/Euclidean_algorithm\">Euclidean algorithm for finding GCD</a>. If you will look into the description or code you will see that it does exactly what is asked in this problem — subtracts numbers one from another. And the result is GCD of original two numbers. So you can see that by some sequence of subtractions you can get GCD.</p></li> <li><p>If you already have d which GCD of all the numbers then you can easily fill all the gaps in { d, 2d, 3d, ..., max } sequence by starting subtracting d from { max, max — d, max — 2d, ... }. So you will get the intended set.</p></li> <li><p>You cannot subtract two numbers a and b which have GCD(a, b) = d and get result which won't be dividable by d. So if you start with set where every numbers can be divided by d then no matter what you subtract you will always have the result which is also dividable by d.</p></li> </ol></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146365 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146365 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146365\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146390\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 16:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146390\" href=\"?#comment-146390\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146390\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146390\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, got it. Thanks!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146390 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146390 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146390\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"774539\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/25/2021 20:24\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-774539\" href=\"?#comment-774539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"774539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-774539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-774539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-774539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-774539\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146310\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i_coder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i_coder\" title=\"Expert i_coder\" class=\"rated-user user-blue\">i_coder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146310\" href=\"?#comment-146310\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146310\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"41979\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146310\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Is this the final editorial (except the D problem) ? The explanations to problems B and C are very limited and not at all well elaborated.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146310 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146310 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146310\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146314\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146314\" href=\"?#comment-146314\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146314\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146314\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can you tell me that why the number of rounds in Problem A will be max(xi)/d-n ? How do you come to this point ? can you please tell me this as am not to figure out this thing ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146314 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146314 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146314\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146316\" commentParentId=\"146314\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:45\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146316\" href=\"?#comment-146316\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146314\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146316\" revisionCount=\"7\" revision=\"7\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">7</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146316\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146316\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>take example <br /> 3 9 54 <br /> gcd (3, 9, 54) = 3 <br /> Now total rounds possible including (3, 9, 54) =<br />all multiples of 3 upto 54 <br /> 3, 6, 9, 12, 15, 18 ... 54 <br /> </p><p>So total count of these numbers = 54 / 3 = 18. <br /> </p><p>Now as out of these numbers 3 numbers are already taken, so subtract 3 <br /> so rounds remaining = 18 — 3 = 15 </p><p>Now it is very easy to generalize for 3 being d and 54 being n</p><p>answer would be n / d — n. <br /> I hope it is clear now :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146316 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146316 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146316\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146319\" commentParentId=\"146316\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146319\" href=\"?#comment-146319\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146316\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146319\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146319\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes, it is more clear to me now. but one thing is that how did you approach to gcd thing ? I understood the problem, the logic and all. how did you approach that it will be done using gcd thing and all ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146319 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146319 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146319\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146322\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146322\" href=\"?#comment-146322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146322\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My Ideas during solving the problem: <br /> all the examples had gcd 1. So I directly thought answer as max(xi) — n. <br /> But I thought it can not be too simple, I need to think more. <br /> So I took a case 2 4 6, I immediately found I am wrong in this case. <br /> Then the idea came into mind that if gcd of numbers is g. then we can not create any number not divisible by g because (g *k1 — k * k2) = g * (k1 — k2). </p><p>So Finally I coded it and got accpeted :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146322\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146338\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 19:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146338\" href=\"?#comment-146338\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146338\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146338\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>given the numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>, what is the minimum positive value you can achieve by combining them? </p><p>Let's write down the equation: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>·<i>x</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub>·<i>x</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>n</i></sub>·<i>x</i><sub class=\"lower-index\"><i>n</i></sub> = <i>d</i></span>, where <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> are some unknown integers. </p><p>It is, as you can see, none other than linear Diophantine equation. And it is known there is no solutions if <span class=\"tex-span\"><i>d</i></span> is not a multiple of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span> </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146338 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146338 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146338\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146317\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/subway\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123924/avatar/706e86f587cbabf0.jpg'/> </a>\n <div><a href=\"/profile/subway\" title=\"Expert subway\" class=\"rated-user user-blue\">subway</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146317\" href=\"?#comment-146317\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146317\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146317\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@hellodear-the final set will contain all elements {d,2d,3d,..max(Xi)} (d=gcd of all elements) so total no. of elements in final set =max(Xi)/d since initially we have 'n' elements total no. of new elements to be added in set to make it complete=(max(Xi)/d)-n.. hope this helps you..:)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146317 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146317 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146317\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146320\" commentParentId=\"146317\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146320\" href=\"?#comment-146320\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146317\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146320\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146320\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in this thing, I was applying some game theory, but it doesn't include anything like that. when the question says optimally, then how do you form examples so as to test your code on them ? because optimally means in the best they can. can you elaborate ? thanks to you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146320 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146320 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146320\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146324\" commentParentId=\"146320\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146324\" href=\"?#comment-146324\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146320\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146324\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146324\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146324\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>optimality argument is simple and also given in the editorial itself. <br /> As total you numbers finally would be {d, 2 * d,, .,, max (xi)}. <br /> Hence whatever you add to the these set, no other person will be able to add that as he has to add a new number everytime to this test. <br /> So outcome depend on the parity of turns.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146324 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146324 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146324\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146325\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sinamosavi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/87557/avatar/bde58fa97bcc5eb0.jpg'/> </a>\n <div><a href=\"/profile/sinamosavi\" title=\"Pupil sinamosavi\" class=\"rated-user user-green\">sinamosavi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146325\" href=\"?#comment-146325\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146325\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"87557\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146325\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the complete proof for A.Div1 is not that much straightforward. Maybe I'm making it too much difficult, but this is my complete proof:</p><p>First by induction, we prove that the numbers in the end will be <span class=\"tex-span\"><i>a</i>, 2<i>a</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Let <span class=\"tex-span\"><i>g</i> = <i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ... , <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span>. It's trivial that in the end <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>. Assume that <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>, because our numbers will be <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), 2<i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>, so we would have a new gcd. That's a contradiction, so <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) = <i>g</i></span> and our numbers will be <span class=\"tex-span\"><i>g</i>, 2<i>g</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Each move adds one number and in the end there will be <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e6ac12549498d8aaad3d63270d12497bc74a9f84.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> numbers, so the answer wil be the parity of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/48ba1bfd0fa315ab1595947b8e046b4cc211b908.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Sorry for my bad English.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146325 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146325 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146325\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146332\" commentParentId=\"146325\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146332\" href=\"?#comment-146332\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146325\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146332\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-13\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146332\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What about this test <code>2 3 5</code>? <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≠ <i>gcd</i></span></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146332 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146332 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146332\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146333\" commentParentId=\"146332\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146333\" href=\"?#comment-146333\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146332\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146333\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146333\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Oops. You've meant that <span class=\"tex-span\"><i>a</i></span> — is the result. Sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146333 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146333 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146333\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146334\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 16:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146334\" href=\"?#comment-146334\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146334\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146334\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146334\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>But how to prove that there is always a way to choose <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> while the number of the current round less than the maximum number of rounds? (Div2C)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146334 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146334 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146334\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146339\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:22\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146339\" href=\"?#comment-146339\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146339\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146339\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146339\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If gcd{xi}＝1, then for every xi there must exist ti to make sum｛xi*ti｝＝1. </p><p>(For example, x1＝5,x2＝7,then t1＝3,t2＝-2.x1*t1＋x2*t2＝1.)</p><p>And sum{xi*ti} can be performed in a few turns. ( (5-(7-5))-(7-5). )</p><p>And if we can get 1, then what number between [1,max{xi}] can't we get？</p><p>if gcd{xi}≠1.the proof is similar.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146339 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146339 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146339\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146341\" commentParentId=\"146339\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146341\" href=\"?#comment-146341\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146339\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146341\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146341\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why there is must exist such t[i]?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146341 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146341 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146341\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146366\" commentParentId=\"146341\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146366\" href=\"?#comment-146366\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146341\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146366\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146366\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You must know if gcd(a,b)＝1, there must exist x and y to make ax＋by＝1. It can be proved from this.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146366 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146366 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146366\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146376\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146376\" href=\"?#comment-146376\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146376\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146376\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146376\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So.. If we divide all the numbers by GCD, and after that a pair of coprime numbers have appeared, we always can reach 1. Let's choose coprime <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, then <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> will be also coprime with <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, and it will be less then <span class=\"tex-span\"><i>max</i>(<i>x</i>, <i>y</i>)</span>. So we can choose <span class=\"tex-span\"><i>mid</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>x</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>min</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>y</i><sub class=\"lower-index\">1</sub></span>, and they are coprime, and <span class=\"tex-span\">|<i>x</i><sub class=\"lower-index\">1</sub> - <i>y</i><sub class=\"lower-index\">1</sub>|</span> will be less than <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>. And etc. by induction. But what to do if there is not a pair of coprime numbers after dividing by GCD? For example <code>35 45 63</code>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146376 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146376 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146376\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146404\" commentParentId=\"146376\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146404\" href=\"?#comment-146404\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146376\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146404\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146404\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146404\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>63*2＋45*5＋35*(-10)＝1</p><p>Because gcd (35,45)＝5, we can consider 35 and 45 as one number 5x. Because gcd(5,63)＝1, so there must exist x,y to make 5x＋63y＝1.</p><p>So here comes a tragedy. We can get 5 first. Then we use this number together with 63 to make 1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146404 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146404 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146404\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146346\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KiAsaGibona\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/KiAsaGibona\" title=\"Specialist KiAsaGibona\" class=\"rated-user user-cyan\">KiAsaGibona</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 21:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146346\" href=\"?#comment-146346\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146346\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146346\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"99053\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146346\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Someone please explain the greedy idea of (Div 1 C) (Number Transformation II). Thanks in advance :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146346 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146346 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146346\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146367\" commentParentId=\"146346\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 09:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146367\" href=\"?#comment-146367\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146346\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146367\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146367\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's a pretty simple greedy idea: Just pick the <code>x</code> that makes the value of <code>a</code> smallest after applying the operation <code>a = a - a%x</code> (or subtract 1 if no choice for <code>x</code> makes <code>a</code> smaller). The proof why this works is given in the editorial: it is never better to get a larger number, so you should get the smallest one you can.</p><p>As listed on the last paragraph of the editorial you have to be careful to remove all <code>x</code> that are either duplicates or cannot be used anymore (<code>a - (a%x)</code> is smaller than <code>b</code>), otherwise you will get TLE.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146367 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146367 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146367\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146382\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146382\" href=\"?#comment-146382\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146382\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146382\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146382\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>how to find this x for each number?</p><p>we will iterate on all x[i]s and only delete x[i]s when x[i] > a?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146382 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146382 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146382\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146405\" commentParentId=\"146382\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146405\" href=\"?#comment-146405\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146382\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146405\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146405\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Iterate through all x[i]s and delete them when a — (a%x[i]) is smaller than b (if you only delete when x[i] > a, you will also get TLE).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146405 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146405 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146405\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146625\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 17:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146625\" href=\"?#comment-146625\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146625\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146625\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm really striving to understand why the algorithm turns out to be linear instead of quadratic... I know the editorial says "That is because, we could cut exactly <span class=\"tex-span\"><i>max</i>{<i>xi</i>}</span> in each 2 step.", but I can't really get what it means :\\</p><p>Can you give me a hint? Thanks :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146625 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146625 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146625\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146643\" commentParentId=\"146625\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/xenoslash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88090/avatar/f75f8cbc20d6133f.jpg'/> </a>\n <div><a href=\"/profile/xenoslash\" title=\"Expert xenoslash\" class=\"rated-user user-blue\">xenoslash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 19:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146643\" href=\"?#comment-146643\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146625\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146643\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146643\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"88090\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146643\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have an easy intuition of cutting at least max{xi} in O(1) steps, not sure what was the intended 2 step proofs though. I am going to use xi to refer to max{xi}, and assume that proper care is taken to only keep the relevant xi's.</p><p>When we do a-(a % xi), we bring caused a to be the next largest integer <= a that is a multiple of xi, since now new_a % xi = 0. Then, if a is divisible by xi, you can do.., do a-1 (causing it to be non-divisible by xi), then finally a-(a%xi) again. In this 3 step sequence you have brought a down to the next lower multiple of xi, and have essentially cut max{xi} in O(1) number of steps.</p><p>Sample code : <a href=\"//codeforces.com/contest/346/submission/4545367\">http://codeforces.com/contest/346/submission/4545367</a> Yeah I used tree set so it's not exactly O(n).. but hash set keeps giving me TLE :(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146643 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146643 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146643\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146689\" commentParentId=\"146643\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2013 12:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146689\" href=\"?#comment-146689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146643\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you very much, that was really eye-opening! This is why I love Codeforces, great community! :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146689\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146371\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Corvo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/11909/avatar/8404ac1aff5270ec.jpg'/> </a>\n <div><a href=\"/profile/Corvo\" title=\"Pupil Corvo\" class=\"rated-user user-green\">Corvo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 12:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146371\" href=\"?#comment-146371\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146371\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"11909\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146371\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please explain why the problem is solved through the GDC (A)? I tried like <a href=\"https://codeforces.com/contest/347/submission/4535232\">this</a>, but I still can not understand why you can not do. Please give a short test on which the decision falls. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146371 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146371 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146371\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146375\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146375\" href=\"?#comment-146375\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146375\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146375\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><pre><code>3\n14 4 2\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146375 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146375 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146375\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146378\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akashdeep\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/39866/avatar/6f66d1bbe26ef4ca.jpg'/> </a>\n <div><a href=\"/profile/akashdeep\" title=\"International Master akashdeep\" class=\"rated-user user-orange\">akashdeep</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146378\" href=\"?#comment-146378\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146378\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"39866\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146378\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Because only those numbers are possible in the game which are multiple of gcd. See this simplest test case</p> <pre><code>2\n4 6\n</code></pre><p>The only number possible in the game is (6-4) i.e. 2, but in your code u are assuming that somehow these (1,2,3,5) numbers can be obtained which is a wrong assumption.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146378 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146378 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146378\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146408\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/NegaTeeF\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/NegaTeeF\" title=\"Master NegaTeeF\" class=\"rated-user user-orange\">NegaTeeF</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 20:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146408\" href=\"?#comment-146408\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146408\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"65829\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146408\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Explain please, how to do Div1-D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146408 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146408 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146408\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146410\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/irakli_p\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29034/avatar/d879a3156498c6c7.jpg'/> </a>\n <div><a href=\"/profile/irakli_p\" title=\"Expert irakli_p\" class=\"rated-user user-blue\">irakli_p</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 21:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146410\" href=\"?#comment-146410\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146410\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29034\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146410\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i didn't understand Div 2 — D can someone explain it to me please </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146410 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146410 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146410\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146443\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/suiyuan2009\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49923/avatar/9065a92c0b30b883.jpg'/> </a>\n <div><a href=\"/profile/suiyuan2009\" title=\"Master suiyuan2009\" class=\"rated-user user-orange\">suiyuan2009</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 13:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146443\" href=\"?#comment-146443\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146443\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49923\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146443\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>problem B,ac automachine is doing the thing that belong to kmp</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146443 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146443 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146443\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146452\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 17:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146452\" href=\"?#comment-146452\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146452\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146452\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div1_E: Should the "Doodler" jump over the platform which H = P ? I just confused about that.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146452 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146452 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146452\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146480\" commentParentId=\"146452\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 11:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146480\" href=\"?#comment-146480\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146452\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146480\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146480\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OK I got the answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146480 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146480 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146480\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146463\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146463\" href=\"?#comment-146463\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146463\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"44\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+44</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146463\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>still waiting for D tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146463 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146463 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146463\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147566\" commentParentId=\"146463\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/05/2013 05:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147566\" href=\"?#comment-147566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146463\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>.. Update .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147566\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"235917\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/saurabhverma\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/143428/avatar/48808a8d5db775d4.jpg'/> </a>\n <div><a href=\"/profile/saurabhverma\" title=\"Expert saurabhverma\" class=\"rated-user user-blue\">saurabhverma</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2015 20:05\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-235917\" href=\"?#comment-235917\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"235917\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"143428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-235917\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In my approach to problem div1 B, I calculated longest common subsequence, prepended virus to it, calculated the Z function and deleted every character which had z[i] >= virus.size(). I don't think my approach is wrong. Can someone tell me if my code is wrong or the approach has some flaw. Thanks. Submission : <a href=\"//codeforces.com/contest/346/submission/11491420\">http://codeforces.com/contest/346/submission/11491420</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-235917 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-235917 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-235917\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"530287\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arpit4427\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/717924/avatar/90dcbc94a1e57cf.jpg'/> </a>\n <div><a href=\"/profile/arpit4427\" title=\"Expert arpit4427\" class=\"rated-user user-blue\">arpit4427</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/26/2019 14:04\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-530287\" href=\"?#comment-530287\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"530287\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"530287\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"717924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-530287\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone explain how to solve this problem <a href=\"/contest/346/problem/B\" title=\"Codeforces Round 201 (Div. 1)\">346B - Lucky Common Subsequence</a>? I have went thorugh the editorial but I could not understand.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-530287 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-530287 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-530287\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8974\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8974 = true;\r\nvar lastPreviewContent8974 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8974] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8974] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:24</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812874998e81759f',t:'MTY5NjcwNTk0NS4wMjkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1753,"cells":{"problem_id":{"kind":"string","value":"347B"},"contest":{"kind":"string","value":"347"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Fixed Points"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Fixed Points</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>A permutation of length <span class=\"tex-span\"><i>n</i></span> is an integer sequence such that each integer from 0 to <span class=\"tex-span\">(<i>n</i> - 1)</span> appears exactly once in it. For example, sequence <span class=\"tex-span\">[0, 2, 1]</span> is a permutation of length 3 while both <span class=\"tex-span\">[0, 2, 2]</span> and <span class=\"tex-span\">[1, 2, 3]</span> are not.</p><p>A fixed point of a function is a point that is mapped to itself by the function. A permutation can be regarded as a bijective function. We'll get a definition of a fixed point in a permutation. An integer <span class=\"tex-span\"><i>i</i></span> is a fixed point of permutation <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">0</sub>, <i>a</i><sub class=\"lower-index\">1</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i> - 1</sub></span> if and only if <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> = <i>i</i></span>. For example, permutation <span class=\"tex-span\">[0, 2, 1]</span> has <span class=\"tex-span\">1</span> fixed point and permutation <span class=\"tex-span\">[0, 1, 2]</span> has <span class=\"tex-span\">3</span> fixed points.</p><p>You are given permutation <span class=\"tex-span\"><i>a</i></span>. You are allowed to swap two elements of the permutation at most once. Your task is to maximize the number of fixed points in the resulting permutation. Note that you are allowed to make at most one swap operation.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a single integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">0</sub>, <i>a</i><sub class=\"lower-index\">1</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i> - 1</sub></span> — the given permutation.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the maximum possible number of fixed points in the permutation after at most one swap operation.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>0 1 3 4 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"1570670537508a85d2a27f0108a26b01\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"f8f8f6cf474a1d90f03554b971b57bc6697e07dd\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='1570670537508a85d2a27f0108a26b01'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F347%2Fproblem%2FB%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='1570670537508a85d2a27f0108a26b01'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/347\">Codeforces Round 201 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='1570670537508a85d2a27f0108a26b01'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/347/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Brute force\">\r\n brute force\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1100\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='1570670537508a85d2a27f0108a26b01'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3509\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='1570670537508a85d2a27f0108a26b01'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3509\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8896\" title=\"Codeforces Round #201\" target=\"_blank\">Codeforces Round #201</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1862:1863\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8903\" title=\"Codeforces Round #201 Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1865\" resourceName=\"Codeforces Round #201 Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/347\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/347/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/347/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/347/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/347/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/347/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/347/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/347/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_ee216976ab166db89da242cd314e90fa7673286a\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Fixed Points</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>A permutation of length <span class=\"tex-span\"><i>n</i></span> is an integer sequence such that each integer from 0 to <span class=\"tex-span\">(<i>n</i> - 1)</span> appears exactly once in it. For example, sequence <span class=\"tex-span\">[0, 2, 1]</span> is a permutation of length 3 while both <span class=\"tex-span\">[0, 2, 2]</span> and <span class=\"tex-span\">[1, 2, 3]</span> are not.</p><p>A fixed point of a function is a point that is mapped to itself by the function. A permutation can be regarded as a bijective function. We'll get a definition of a fixed point in a permutation. An integer <span class=\"tex-span\"><i>i</i></span> is a fixed point of permutation <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">0</sub>, <i>a</i><sub class=\"lower-index\">1</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i> - 1</sub></span> if and only if <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> = <i>i</i></span>. For example, permutation <span class=\"tex-span\">[0, 2, 1]</span> has <span class=\"tex-span\">1</span> fixed point and permutation <span class=\"tex-span\">[0, 1, 2]</span> has <span class=\"tex-span\">3</span> fixed points.</p><p>You are given permutation <span class=\"tex-span\"><i>a</i></span>. You are allowed to swap two elements of the permutation at most once. Your task is to maximize the number of fixed points in the resulting permutation. Note that you are allowed to make at most one swap operation.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a single integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">0</sub>, <i>a</i><sub class=\"lower-index\">1</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i> - 1</sub></span> — the given permutation.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the maximum possible number of fixed points in the permutation after at most one swap operation.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />0 1 3 4 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:54</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bdf50eed00a1',t:'MTY5NjY0NjAzNC44MjAwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Brute force\", \"Implementation problems, programming technics, simulation\", \"Mathematics including integration, differential equations, etc\"]"},"short_tags":{"kind":"string","value":"[\"brute force\", \"implementation\", \"math\", \"*1100\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8903"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"1c88316eb9ff5851524d80ea59ef3f32\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #201 Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #201 Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='1c88316eb9ff5851524d80ea59ef3f32'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8903\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/MinakoKojima\">MinakoKojima</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/MinakoKojima\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/MinakoKojima\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/MinakoKojima\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/MinakoKojima\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/MinakoKojima\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/MinakoKojima\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/MinakoKojima\" style=\"text-decoration:none;color:black !important;\">MinakoKojima's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8958\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8903\"> <p>Codeforces Round #201 Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a>,\r\n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><img alt=\" \" src=\"/predownloaded/41/3f/413f7303374a112dddc1e63e29cfc12924514cd7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><h1>Overview</h1><p>In DIV 1, there are 4 interesting problems together with a normal one. We think it is reasonable because we can't have a round fullly with intelligence. Problem A, C have weak pretests while others intended to be strong. About more then 200 participants solve A in the early 45mins, then a few of them start from C while most of the other start from B. </p><p>Problem B is a rather standard problem, but if you're unfamiliar with the algorithm, it can be very hard. Problem C is a more intersting problem. As the name implies, there was <a href=\"//codeforces.com/problemset/problem/251/C\">a similar version</a> in the previous round before, but this time it has a brand new constrains.(So here we have a psychology experiment: could different constrains make people thinking in a slightly different way?ww)</p><p>The standard solution of problem C is <span class=\"tex-span\"><i>O</i>((<i>b</i> - <i>a</i>) + <i>nlogn</i>)</span>. The first expected correct solution was written by <a class=\"rated-user user-orange\" href=\"/profile/zeliboba\" title=\"International Master zeliboba\">zeliboba</a>. <a href=\"//codeforces.com/contest/346/submission/4512654\">http://codeforces.com/contest/346/submission/4512654</a></p><p>After that, some people start to solve problem D. Problem D looks like a hard dp problem on a graph at the first glance, the key point is how to avoid the circle in the transfer equation. It turn out to be elegant after you could found a right order of the evaluation. Problem E is challenging which you need find a way to transform the original question into a smaller scale, and cut off many many corner cases ... And in the very end, you find a way like binary search to get <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span> as the time complexity. No one manage to solve problem E during the contest, maybe <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> is the man who closest to it.</p><p>The winner comes to <a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"Grandmaster cgy4ever\">cgy4ever</a>, because he found the draw-black in his previous C submission during the very beginning even when there is nobody hack him! He resubmit it decisively and get back when finished problem D. After that, he use the same trick which made him failed before to hack others and got a handsomely rewards. The second place went to <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a>, because of the combination of decent speed in A, B, C, D.</p><p>Problem B belongs to me, problem C belongs to <a class=\"rated-user user-violet\" href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\">CMHJT</a> and others belong to <a class=\"rated-user user-orange\" href=\"/profile/UESTC_Nocturne\" title=\"International Master UESTC_Nocturne\">UESTC_Nocturne</a>. The illustrator of problem C is <a href=\"http://www.pixiv.net/member_illust.php?mode=medium&illust_id=38602657\">Chairman Miao(貓主席)</a>.</p><h1>Editorial</h1><h3><a href=\"//codeforces.com/problemset/problem/346/A\">Problem A. Alice and Bob</a></h3><h4>Brief description:</h4><p>Alice and Bob play a game, the rules are as follows: First, they will get a set of <span class=\"tex-span\"><i>n</i></span> distinct numbers. And then they take turns to do the following operations. During each operation, either Alice or Bob can choose two different numbers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> from the set, as long as <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> is not in the set, then they add it to the set. The person who can not choose two numbers successfully will lose the game. The question is who will finally win the game if both of them do operations optimally. Remember that Alice always goes first.</p><h4>Analysis:</h4><p>First, no matter what happend, the number set we get at the very endding will be same all the time. Let's say <span class=\"tex-span\"><i>d</i> = <i>gcd</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}. Then the set in the endding will be some things like {<span class=\"tex-span\"><i>d</i></span>, <span class=\"tex-span\">2<i>d</i></span>, <span class=\"tex-span\">3<i>d</i></span>, ... <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}}. So there is always <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub>} / <i>d</i></span> — <span class=\"tex-span\"><i>n</i></span> rounds. And what we should do rest is to check the parity of this value.</p><h3><a href=\"//codeforces.com/problemset/problem/346/B\">Problem B. Lucky Common Subsequence</a></h3><h4>Brief description:</h4><p>You have been given two strings <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and <span class=\"tex-span\"><i>virus</i></span>, and you have to find the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> without <span class=\"tex-span\"><i>virus</i></span> as a substring.</p><h4>Analysis:</h4><p>This is a rather classical problem, let's say if there is no virus, then it is the classical **LCS ** problem. You can solve this by a <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> dynamic programing.</p><p>When consider about the virus, we should add 1 more dimension on the state to trace the growth of the virus. It can be done by wheather <strong>Aho-Corasick automation</strong>, or <strong>KMP</strong> when there is only one virus in this case. The overall time complexity is <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">3</sup>)</span>.</p><h3><a href=\"//codeforces.com/problemset/problem/346/C\">Problem C. Number Transformation II</a></h3><h4>Brief description:</h4><p>You have a number <span class=\"tex-span\"><i>b</i></span>, and want to minus it to <span class=\"tex-span\"><i>a</i></span>, what you can do in each step is weather subtract 1 or <span class=\"tex-span\"><i>b</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> from <span class=\"tex-span\"><i>b</i></span>. And we ask what is the minimum number of steps you need.</p><h4>Analysis:</h4><p>I bet there is a few people know the greedy method even if he/she have solved the early version before.</p><p><a href=\"//codeforces.com/problemset/problem/251/C\">Codeforces #153 Div 1. Problem C. Number Transformation</a></p><p>Let dp[k] denotes the minimum number of steps to transform b+k to b. In each step, you could only choose i which makes b+k-(b+k) mod x[i] minimal to calc dp[k]. It works bacause dp[0..k-1] is a monotone increasing function. Proof: - Say dp[k]=dp[k-t]+1.If t==1, then dp[0..k] is monotone increasing obviously.Otherwise dp[k-1]<=dp[k-t]+1=dp[k] (there must exist a x[i] makes b+k-1 also transform to b+k-t,and it is not necessarily the optimal decision of dp[k-1]). So dp[k] is a monotone increasing function, we can greedily calc dp[a-b].</p><p>In the first glance, it looks like something which will run in square complexity. But actually is linear. That is because, we could cut exactly max{<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>} in each 2 step. It can be proof by induction.</p><p>So the remians work is to delete those same <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>, and watch out some situation could cause degeneration. Many of us failed in this last step and got <strong>TLE</strong></p><h3><a href=\"//codeforces.com/problemset/problem/346/D\">Problem D. Robot Control</a></h3><p>Let's dp from t to s.</p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>Here dp[u] means, the minimum number of orders mzry1992 needs to send in the worst case. The left-hand-side is sending order while the right-hand side is not. At the beginning, we have dp[t] = 1, and dp[s] will be the answer.</p><p>We can see there is circular dependence in this equation, in this situation, one standard method is using Bellman-Ford algorithm to evaluate the dp function.</p><p>But it is not appropriate for this problem.</p><p>(In fact, we add a part of targeted datas in pretest, these datas are enough to block most of our <a href=\"https://en.wikipedia.org/wiki/Bellman%E2%80%93Ford_algorithm\">Bellman-Ford algorithm</a>, although there is still a few participator can get accepted by Bellman-Ford algorithm during the contest.</p><p>Check <a class=\"rated-user user-violet\" href=\"/profile/rares.buhai\" title=\"Candidate Master rares.buhai\">rares.buhai</a>'s <a href=\"//codeforces.com/contest/346/submission/4520171\">solution</a></p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>The expected solution is evaluating the dp function as the increased value of dp[u] itself. Further analysis shows, wheather we decided sending order or not in u can be judged as the out-degree of u.</p> <pre><code><br />while (!Q.empty()) {\n u = Q.front(), Q.pop_front()\n for each edge from v to u\n --out_degree[v]\n\tif (out_degree[v] == 0) {\n relax dp[v] by dp[u]\n if success, add v to the front of Q\n\t}\n\telse{\n\t relax dp[v] by dp[u] + 1\n\t if success, add v to the back of Q\n }\t\n }\n</code></pre><p>Check <a class=\"rated-user user-orange\" href=\"/profile/Ra16bit\" title=\"International Master Ra16bit\">Ra16bit</a>'s <a href=\"//codeforces.com/contest/346/submission/4519668\">solution</a> to see how it works.</p><h3><a href=\"//codeforces.com/problemset/problem/346/E\">Problem E. Doodle Jump</a></h3><h4>Brief description:</h4><p>You have been give <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>, <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>h</i></span> (gcd(<span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>) = 1), For each <span class=\"tex-span\"><i>ai</i></span> mod <span class=\"tex-span\"><i>p</i></span>, (<span class=\"tex-span\"><i>i</i></span>∈[1, n]), check weather the maximum distance in neighborhood after sorting is <= <span class=\"tex-span\"><i>h</i></span>. </p><h4>Analysis:</h4><p>Take <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 for example ... Divided the numbers in group.</p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 18\n</code></pre><p>We start a new group when the number > P</p><p>We found the difference between the elements of the first group is 5, The subsequent is filling some gap between the them ...</p><p>After some observation we could found that we should only consider into one gap ...(e.g. [0, 5] or [15, 20] or [20, 25] ... ) </p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>That says .. <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 is roughly equal to some things in small scale?</p><p>So let's check it in detail. Lemma 1. In any case, the gap after 20 won't better than any gap before it.</p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>For example, in this case, the gap after 20 is: 20, 22 And it has 16 in [15, 17] but no 21. </p><p>Is there any chance that [20, 23] is better than [15, 20]?</p><p>No, that is because, when there is no 21, then (19+5)%23 = 1, go to next floor. and there is no corresponding gap after 20 ([22, 24]) for this gap ([17, 19])</p><p>So we only need to consider [15, 20] ... and we found [15, 20] is roughly equal to [0, 5]</p> <pre><code>e.g. : 15 20 17 19 16 18 \nequal: 0 5 2 4 1 3\n</code></pre><p>we say 'roughly' because we havn't check some boundary case like there is 3 but on 18 ... </p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 \n</code></pre><p>If it happend, we should remove the number 3. .. If we can remove the element 5, then we can from a=5, p=23 to a'=2, p'=5 ...(n' = an/p, a' = a-p%a, if there is 3 but no 18, n'=n'-1)</p><p>The rest things is to discuss wheather 5 is necessary or not.</p><p>Let's we have:</p> <pre><code>0 2 4\n1 3\n</code></pre><p>If the 2*n'<5, then there is only one floor, the answer is max(2, 5-2*n'). If there is more than one floor, we could conclude that 5 is useless.</p><p>Proof: Elemets in 1st floor is: </p> <pre><code>0 a 2a 3a ...\n</code></pre><p>Let's say the maximum elements in 1st floor is x, then the minimum element in the 2nd floor is b0 = x+a-p, because b0 — a = x-p, so the difference between b0 and a is equal to the difference between x and p. That is, we can consider [b0, a] rather than [x, p], when there is a element insert in [b0, a], there must be some element insert in [x, p] in the same position.</p><p>So we have have succeeded to transform our original problem into a small one. Of couse, this problem havn't been solved, we haven't consider the time complexity. Says a' = a — p%a, when p = a+1, then a' = a-1, but we have <span class=\"tex-span\"><i>a</i></span> equal to 10^9, it won't work.</p><p>But, let's we have A1, A2, ... An ... and we subtract <span class=\"tex-span\"><i>d</i></span> from all of them, the answer won't be changed. So we can use p%a substitute for a-p%a, this is equivalent to we subtract %p% from all of them ...</p><p>So we set a' = min(a-p%a, p%a), so a'<=a/2, therefore, the final time complexity is <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span>.</p><p>You can check <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> <a href=\"//codeforces.com/contest/346/submission/4523388\">'s solution</a> for detail.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/346\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/347\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-4906-8958\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"4906\",\n blogEntryId: \"8903\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+56</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/MinakoKojima\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/MinakoKojima\">\n MinakoKojima\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8903#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8903#comments\">\n 66\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8974\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (56)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146290\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mohammadrdeh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/47/avatar/91eee3f7a5ec41f6.jpg'/> </a>\n <div><a href=\"/profile/mohammadrdeh\" title=\"Specialist mohammadrdeh\" class=\"rated-user user-cyan\">mohammadrdeh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146290\" href=\"?#comment-146290\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146290\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"14\"\r\n data-commentUserId=\"47\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+14</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146290\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>there is a typo: "... the classical <strong>LCA</strong> problem ..." => <strong>LCS</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146290 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146290 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146290\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146291\" commentParentId=\"146290\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146291\" href=\"?#comment-146291\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146290\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146291\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146291\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you. Fixed. m(_ _)m</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146291 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146291 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146291\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146297\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 05:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146297\" href=\"?#comment-146297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Actually our standard solution to C is O(b-a+n). O(b-a+n),O(b-a+nlogn),O((b-a+n)logn) are all able to pass during the test.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146297\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146335\" commentParentId=\"146297\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mmaxio\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/486/avatar/4bb53c24fc9e4c1.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/mmaxio\" title=\"International Master mmaxio\" class=\"rated-user user-orange\">mmaxio</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 17:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146335\" href=\"?#comment-146335\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146297\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146335\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146335\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"486\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146335\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>oh, never mind</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146335 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146335 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146335\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146299\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shashwat.gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6204/avatar/67f8e17c53f70578.jpg'/> </a>\n <div><a href=\"/profile/shashwat.gupta\" title=\"Specialist shashwat.gupta\" class=\"rated-user user-cyan\">shashwat.gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146299\" href=\"?#comment-146299\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146299\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"6204\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146299\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Problem B: Can you Explain little bit more on How "Aho-Corasick automation, or KMP" can help in figuring out smallest string that does not contain virus.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146299 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146299 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146299\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146300\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146300\" href=\"?#comment-146300\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146300\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146300\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For B, I already had the intuitive idea that this problem will be solved by either Aho-Corasick algorithm or KMP with dp, but I could not formalize the idea of states transition in dp. Could you please just provide the state in your dp algorithm?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146300 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146300 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146300\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146354\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146354\" href=\"?#comment-146354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146354\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Original problem can be solved by dp with two parameters DP[Len(s)] [Len(t)]. <a href=\"https://en.wikipedia.org/wiki/Longest_common_subsequence_problem\">http://en.wikipedia.org/wiki/Longest_common_subsequence_problem</a></p><p>To solve B you need to modificate it to DP[Len(s)][Len(t)][Len(virus)-1] where third parameter means maximum length of suffix of LCS that equal to prefix of virus.</p><p>To easy check where we go from K state (third parameter) by character C we can make automat on prefix function by virus.</p><p>Then if we stand in DP[i][j][k] :<br /> 1) if(s[i] == t[j] and Automat[k][c]<Len(virus) we try to relax DP[i+1][j+1][Automat[k][c]]<br /> 2) Try to relax DP[i][j+1][k] and DP[i+1][j][k]</p><p><strong>UPD</strong> My solution: <a href=\"//codeforces.com/contest/346/submission/4532899\">http://codeforces.com/contest/346/submission/4532899</a> (hope it understandable)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146354\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146357\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146357\" href=\"?#comment-146357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>got it, many thanks to you man :) Also understood why KMP tag mentioned in the problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146357\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146493\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lama\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/72190/avatar/735906a91d1576e3.jpg'/> </a>\n <div><a href=\"/profile/lama\" title=\"Expert lama\" class=\"rated-user user-blue\">lama</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 18:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146493\" href=\"?#comment-146493\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146493\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146493\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) Can you please explain what "maximum length of suffix of LCS that equal to prefix of virus" means? 2) What is an automat?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146493 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146493 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146493\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146519\" commentParentId=\"146493\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/25/2013 05:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146519\" href=\"?#comment-146519\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146493\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146519\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146519\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146519\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) We stand in DP[i][j][k]-state (in which we store longest LCS), virus = "virus" <br /> Let's go from k = 0 to 4,then:</p> <pre><code>0) DP[i][j][0] means that finded LCS not ends on "v" or "vi" or "vir" or "viru" or "virus". (example: "a")\n\n1) DP[i][j][1] means that finded LCS ends on "v", but not on "vi" or "vir" or "viru" or "virus". (example: "av")\n\n2) DP[i][j][2] means that finded LCS ends on "vi", but not on "vir" or "viru" or "virus". (example: "avi")\t\n\n3) DP[i][j][3] means that finded LCS ends on "vir", but not on "viru" or "virus". (example: "avir")\n\n4) DP[i][j][4] means that finded LCS ends on "viru", but not on "virus". (example: "aviru")\n\nWe take "longest suffix of LCS that equal prefix of virus", because virus could be: "vvvvv" or "ababv" (and infinite others)\n If LCS = "avvv" - it ends on "v","vv","vvv". (virus = "vvvvv")\n If LCS = "aabab" - it ends on "ab" and "abab". (virus = "ababv")\n</code></pre><p><a href=\"https://en.wikipedia.org/wiki/Knuth%E2%80%93Morris%E2%80%93Pratt_algorithm\">KMP</a></p><p>2) <a href=\"https://en.wikipedia.org/wiki/Automata_theory\">http://en.wikipedia.org/wiki/Automata_theory</a></p><p>Can't find nothing about automaton on prefix-function in english. I hope you will be able understand <a href=\"http://e-maxx.ru/algo/prefix_function\">this</a> with some translator (google translate for example).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146519 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146519 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146519\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"551712\" commentParentId=\"146519\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/srv_twry\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/447741/avatar/d1a80b00eb029c2b.jpg'/> </a>\n <div><a href=\"/profile/srv_twry\" title=\"Expert srv_twry\" class=\"rated-user user-blue\">srv_twry</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/19/2019 12:58\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-551712\" href=\"?#comment-551712\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146519\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"551712\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"447741\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-551712\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Fortunately, the e-maxx article on Prefix function has been translated in English and can be found here: <a href=\"https://cp-algorithms.com/string/prefix-function.html#toc-tgt-12\">prefix-function: automaton on prefix-function</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-551712 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-551712 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-551712\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"768401\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ttbbnnn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1694563/avatar/ff85df0301cf6f76.jpg'/> </a>\n <div><a href=\"/profile/ttbbnnn\" title=\"Master ttbbnnn\" class=\"rated-user user-orange\">ttbbnnn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2021 20:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-768401\" href=\"?#comment-768401\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"768401\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1694563\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-768401\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My solution for B got a WA on test 41 and I don't know why :<, please help me with this code: <a href=\"https://codeforces.com/contest/346/submission/109283664\">https://codeforces.com/contest/346/submission/109283664</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-768401 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-768401 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-768401\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146301\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146301\" href=\"?#comment-146301\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146301\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146301\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146301\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"So the remians work is to delete those same xi, and watch out some situation could cause degeneration. Many of us failed in this last step and got TLE", I really could not understand this. What you you mean by degeneration in this case? Please explain this last important step.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146301 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146301 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146301\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146302\" commentParentId=\"146301\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:37\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146302\" href=\"?#comment-146302\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146301\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146302\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146302\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>suppose b=1, all x[i]>a, what will happen?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146302 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146302 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146302\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146304\" commentParentId=\"146302\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146304\" href=\"?#comment-146304\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146302\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146304\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146304\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As b = 1, All x[i] > a. Then a % x[i] = a. So if we take this, then we will lead to a — a = 0, which is less than b. So we need to move one by one, so answer would be a.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146304 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146304 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146304\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146309\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146309\" href=\"?#comment-146309\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146309\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146309\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Alice and Bob problem how do you prove that you will always get {d, 2d, 3d, ... max{xi}} in the end. It is easy to see but I am unable to prove it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146309 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146309 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146309\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146365\" commentParentId=\"146309\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marat.snowbear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98082/avatar/1499cf6d0c86172.jpg'/> </a>\n <div><a href=\"/profile/marat.snowbear\" title=\"International Master marat.snowbear\" class=\"rated-user user-orange\">marat.snowbear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146365\" href=\"?#comment-146365\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146309\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146365\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"98082\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146365\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I convinced myself like this:</p> <ol> <li>Prove that we will be able to get d by some sequence of subtractions.</li> <li>Prove that we will be able to generate {d, 2d, 3d, ...}</li> <li>Prove that we will not be able to get anything else except for { d, 2d, 3d, ... }</li> </ol><p>In details:</p> <ol> <li><p>See <a href=\"https://en.wikipedia.org/wiki/Euclidean_algorithm\">Euclidean algorithm for finding GCD</a>. If you will look into the description or code you will see that it does exactly what is asked in this problem — subtracts numbers one from another. And the result is GCD of original two numbers. So you can see that by some sequence of subtractions you can get GCD.</p></li> <li><p>If you already have d which GCD of all the numbers then you can easily fill all the gaps in { d, 2d, 3d, ..., max } sequence by starting subtracting d from { max, max — d, max — 2d, ... }. So you will get the intended set.</p></li> <li><p>You cannot subtract two numbers a and b which have GCD(a, b) = d and get result which won't be dividable by d. So if you start with set where every numbers can be divided by d then no matter what you subtract you will always have the result which is also dividable by d.</p></li> </ol></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146365 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146365 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146365\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146390\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 16:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146390\" href=\"?#comment-146390\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146390\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146390\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, got it. Thanks!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146390 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146390 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146390\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"774539\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/25/2021 20:24\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-774539\" href=\"?#comment-774539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"774539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-774539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-774539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-774539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-774539\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146310\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i_coder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i_coder\" title=\"Expert i_coder\" class=\"rated-user user-blue\">i_coder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146310\" href=\"?#comment-146310\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146310\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"41979\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146310\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Is this the final editorial (except the D problem) ? The explanations to problems B and C are very limited and not at all well elaborated.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146310 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146310 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146310\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146314\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146314\" href=\"?#comment-146314\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146314\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146314\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can you tell me that why the number of rounds in Problem A will be max(xi)/d-n ? How do you come to this point ? can you please tell me this as am not to figure out this thing ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146314 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146314 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146314\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146316\" commentParentId=\"146314\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:45\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146316\" href=\"?#comment-146316\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146314\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146316\" revisionCount=\"7\" revision=\"7\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">7</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146316\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146316\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>take example <br /> 3 9 54 <br /> gcd (3, 9, 54) = 3 <br /> Now total rounds possible including (3, 9, 54) =<br />all multiples of 3 upto 54 <br /> 3, 6, 9, 12, 15, 18 ... 54 <br /> </p><p>So total count of these numbers = 54 / 3 = 18. <br /> </p><p>Now as out of these numbers 3 numbers are already taken, so subtract 3 <br /> so rounds remaining = 18 — 3 = 15 </p><p>Now it is very easy to generalize for 3 being d and 54 being n</p><p>answer would be n / d — n. <br /> I hope it is clear now :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146316 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146316 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146316\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146319\" commentParentId=\"146316\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146319\" href=\"?#comment-146319\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146316\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146319\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146319\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes, it is more clear to me now. but one thing is that how did you approach to gcd thing ? I understood the problem, the logic and all. how did you approach that it will be done using gcd thing and all ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146319 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146319 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146319\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146322\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146322\" href=\"?#comment-146322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146322\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My Ideas during solving the problem: <br /> all the examples had gcd 1. So I directly thought answer as max(xi) — n. <br /> But I thought it can not be too simple, I need to think more. <br /> So I took a case 2 4 6, I immediately found I am wrong in this case. <br /> Then the idea came into mind that if gcd of numbers is g. then we can not create any number not divisible by g because (g *k1 — k * k2) = g * (k1 — k2). </p><p>So Finally I coded it and got accpeted :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146322\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146338\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 19:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146338\" href=\"?#comment-146338\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146338\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146338\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>given the numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>, what is the minimum positive value you can achieve by combining them? </p><p>Let's write down the equation: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>·<i>x</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub>·<i>x</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>n</i></sub>·<i>x</i><sub class=\"lower-index\"><i>n</i></sub> = <i>d</i></span>, where <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> are some unknown integers. </p><p>It is, as you can see, none other than linear Diophantine equation. And it is known there is no solutions if <span class=\"tex-span\"><i>d</i></span> is not a multiple of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span> </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146338 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146338 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146338\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146317\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/subway\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123924/avatar/706e86f587cbabf0.jpg'/> </a>\n <div><a href=\"/profile/subway\" title=\"Expert subway\" class=\"rated-user user-blue\">subway</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146317\" href=\"?#comment-146317\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146317\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146317\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@hellodear-the final set will contain all elements {d,2d,3d,..max(Xi)} (d=gcd of all elements) so total no. of elements in final set =max(Xi)/d since initially we have 'n' elements total no. of new elements to be added in set to make it complete=(max(Xi)/d)-n.. hope this helps you..:)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146317 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146317 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146317\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146320\" commentParentId=\"146317\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146320\" href=\"?#comment-146320\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146317\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146320\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146320\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in this thing, I was applying some game theory, but it doesn't include anything like that. when the question says optimally, then how do you form examples so as to test your code on them ? because optimally means in the best they can. can you elaborate ? thanks to you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146320 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146320 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146320\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146324\" commentParentId=\"146320\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146324\" href=\"?#comment-146324\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146320\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146324\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146324\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146324\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>optimality argument is simple and also given in the editorial itself. <br /> As total you numbers finally would be {d, 2 * d,, .,, max (xi)}. <br /> Hence whatever you add to the these set, no other person will be able to add that as he has to add a new number everytime to this test. <br /> So outcome depend on the parity of turns.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146324 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146324 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146324\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146325\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sinamosavi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/87557/avatar/bde58fa97bcc5eb0.jpg'/> </a>\n <div><a href=\"/profile/sinamosavi\" title=\"Pupil sinamosavi\" class=\"rated-user user-green\">sinamosavi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146325\" href=\"?#comment-146325\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146325\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"87557\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146325\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the complete proof for A.Div1 is not that much straightforward. Maybe I'm making it too much difficult, but this is my complete proof:</p><p>First by induction, we prove that the numbers in the end will be <span class=\"tex-span\"><i>a</i>, 2<i>a</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Let <span class=\"tex-span\"><i>g</i> = <i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ... , <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span>. It's trivial that in the end <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>. Assume that <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>, because our numbers will be <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), 2<i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>, so we would have a new gcd. That's a contradiction, so <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) = <i>g</i></span> and our numbers will be <span class=\"tex-span\"><i>g</i>, 2<i>g</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Each move adds one number and in the end there will be <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e6ac12549498d8aaad3d63270d12497bc74a9f84.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> numbers, so the answer wil be the parity of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/48ba1bfd0fa315ab1595947b8e046b4cc211b908.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Sorry for my bad English.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146325 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146325 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146325\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146332\" commentParentId=\"146325\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146332\" href=\"?#comment-146332\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146325\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146332\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-13\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146332\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What about this test <code>2 3 5</code>? <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≠ <i>gcd</i></span></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146332 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146332 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146332\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146333\" commentParentId=\"146332\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146333\" href=\"?#comment-146333\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146332\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146333\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146333\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Oops. You've meant that <span class=\"tex-span\"><i>a</i></span> — is the result. Sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146333 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146333 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146333\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146334\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 16:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146334\" href=\"?#comment-146334\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146334\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146334\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146334\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>But how to prove that there is always a way to choose <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> while the number of the current round less than the maximum number of rounds? (Div2C)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146334 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146334 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146334\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146339\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:22\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146339\" href=\"?#comment-146339\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146339\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146339\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146339\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If gcd{xi}＝1, then for every xi there must exist ti to make sum｛xi*ti｝＝1. </p><p>(For example, x1＝5,x2＝7,then t1＝3,t2＝-2.x1*t1＋x2*t2＝1.)</p><p>And sum{xi*ti} can be performed in a few turns. ( (5-(7-5))-(7-5). )</p><p>And if we can get 1, then what number between [1,max{xi}] can't we get？</p><p>if gcd{xi}≠1.the proof is similar.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146339 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146339 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146339\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146341\" commentParentId=\"146339\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146341\" href=\"?#comment-146341\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146339\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146341\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146341\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why there is must exist such t[i]?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146341 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146341 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146341\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146366\" commentParentId=\"146341\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146366\" href=\"?#comment-146366\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146341\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146366\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146366\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You must know if gcd(a,b)＝1, there must exist x and y to make ax＋by＝1. It can be proved from this.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146366 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146366 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146366\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146376\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146376\" href=\"?#comment-146376\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146376\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146376\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146376\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So.. If we divide all the numbers by GCD, and after that a pair of coprime numbers have appeared, we always can reach 1. Let's choose coprime <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, then <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> will be also coprime with <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, and it will be less then <span class=\"tex-span\"><i>max</i>(<i>x</i>, <i>y</i>)</span>. So we can choose <span class=\"tex-span\"><i>mid</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>x</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>min</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>y</i><sub class=\"lower-index\">1</sub></span>, and they are coprime, and <span class=\"tex-span\">|<i>x</i><sub class=\"lower-index\">1</sub> - <i>y</i><sub class=\"lower-index\">1</sub>|</span> will be less than <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>. And etc. by induction. But what to do if there is not a pair of coprime numbers after dividing by GCD? For example <code>35 45 63</code>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146376 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146376 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146376\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146404\" commentParentId=\"146376\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146404\" href=\"?#comment-146404\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146376\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146404\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146404\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146404\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>63*2＋45*5＋35*(-10)＝1</p><p>Because gcd (35,45)＝5, we can consider 35 and 45 as one number 5x. Because gcd(5,63)＝1, so there must exist x,y to make 5x＋63y＝1.</p><p>So here comes a tragedy. We can get 5 first. Then we use this number together with 63 to make 1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146404 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146404 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146404\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146346\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KiAsaGibona\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/KiAsaGibona\" title=\"Specialist KiAsaGibona\" class=\"rated-user user-cyan\">KiAsaGibona</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 21:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146346\" href=\"?#comment-146346\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146346\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146346\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"99053\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146346\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Someone please explain the greedy idea of (Div 1 C) (Number Transformation II). Thanks in advance :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146346 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146346 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146346\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146367\" commentParentId=\"146346\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 09:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146367\" href=\"?#comment-146367\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146346\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146367\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146367\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's a pretty simple greedy idea: Just pick the <code>x</code> that makes the value of <code>a</code> smallest after applying the operation <code>a = a - a%x</code> (or subtract 1 if no choice for <code>x</code> makes <code>a</code> smaller). The proof why this works is given in the editorial: it is never better to get a larger number, so you should get the smallest one you can.</p><p>As listed on the last paragraph of the editorial you have to be careful to remove all <code>x</code> that are either duplicates or cannot be used anymore (<code>a - (a%x)</code> is smaller than <code>b</code>), otherwise you will get TLE.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146367 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146367 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146367\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146382\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146382\" href=\"?#comment-146382\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146382\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146382\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146382\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>how to find this x for each number?</p><p>we will iterate on all x[i]s and only delete x[i]s when x[i] > a?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146382 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146382 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146382\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146405\" commentParentId=\"146382\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146405\" href=\"?#comment-146405\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146382\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146405\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146405\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Iterate through all x[i]s and delete them when a — (a%x[i]) is smaller than b (if you only delete when x[i] > a, you will also get TLE).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146405 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146405 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146405\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146625\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 17:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146625\" href=\"?#comment-146625\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146625\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146625\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm really striving to understand why the algorithm turns out to be linear instead of quadratic... I know the editorial says "That is because, we could cut exactly <span class=\"tex-span\"><i>max</i>{<i>xi</i>}</span> in each 2 step.", but I can't really get what it means :\\</p><p>Can you give me a hint? Thanks :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146625 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146625 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146625\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146643\" commentParentId=\"146625\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/xenoslash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88090/avatar/f75f8cbc20d6133f.jpg'/> </a>\n <div><a href=\"/profile/xenoslash\" title=\"Expert xenoslash\" class=\"rated-user user-blue\">xenoslash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 19:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146643\" href=\"?#comment-146643\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146625\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146643\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146643\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"88090\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146643\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have an easy intuition of cutting at least max{xi} in O(1) steps, not sure what was the intended 2 step proofs though. I am going to use xi to refer to max{xi}, and assume that proper care is taken to only keep the relevant xi's.</p><p>When we do a-(a % xi), we bring caused a to be the next largest integer <= a that is a multiple of xi, since now new_a % xi = 0. Then, if a is divisible by xi, you can do.., do a-1 (causing it to be non-divisible by xi), then finally a-(a%xi) again. In this 3 step sequence you have brought a down to the next lower multiple of xi, and have essentially cut max{xi} in O(1) number of steps.</p><p>Sample code : <a href=\"//codeforces.com/contest/346/submission/4545367\">http://codeforces.com/contest/346/submission/4545367</a> Yeah I used tree set so it's not exactly O(n).. but hash set keeps giving me TLE :(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146643 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146643 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146643\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146689\" commentParentId=\"146643\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2013 12:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146689\" href=\"?#comment-146689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146643\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you very much, that was really eye-opening! This is why I love Codeforces, great community! :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146689\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146371\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Corvo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/11909/avatar/8404ac1aff5270ec.jpg'/> </a>\n <div><a href=\"/profile/Corvo\" title=\"Pupil Corvo\" class=\"rated-user user-green\">Corvo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 12:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146371\" href=\"?#comment-146371\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146371\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"11909\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146371\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please explain why the problem is solved through the GDC (A)? I tried like <a href=\"https://codeforces.com/contest/347/submission/4535232\">this</a>, but I still can not understand why you can not do. Please give a short test on which the decision falls. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146371 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146371 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146371\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146375\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146375\" href=\"?#comment-146375\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146375\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146375\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><pre><code>3\n14 4 2\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146375 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146375 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146375\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146378\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akashdeep\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/39866/avatar/6f66d1bbe26ef4ca.jpg'/> </a>\n <div><a href=\"/profile/akashdeep\" title=\"International Master akashdeep\" class=\"rated-user user-orange\">akashdeep</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146378\" href=\"?#comment-146378\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146378\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"39866\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146378\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Because only those numbers are possible in the game which are multiple of gcd. See this simplest test case</p> <pre><code>2\n4 6\n</code></pre><p>The only number possible in the game is (6-4) i.e. 2, but in your code u are assuming that somehow these (1,2,3,5) numbers can be obtained which is a wrong assumption.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146378 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146378 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146378\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146408\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/NegaTeeF\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/NegaTeeF\" title=\"Master NegaTeeF\" class=\"rated-user user-orange\">NegaTeeF</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 20:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146408\" href=\"?#comment-146408\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146408\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"65829\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146408\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Explain please, how to do Div1-D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146408 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146408 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146408\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146410\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/irakli_p\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29034/avatar/d879a3156498c6c7.jpg'/> </a>\n <div><a href=\"/profile/irakli_p\" title=\"Expert irakli_p\" class=\"rated-user user-blue\">irakli_p</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 21:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146410\" href=\"?#comment-146410\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146410\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29034\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146410\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i didn't understand Div 2 — D can someone explain it to me please </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146410 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146410 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146410\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146443\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/suiyuan2009\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49923/avatar/9065a92c0b30b883.jpg'/> </a>\n <div><a href=\"/profile/suiyuan2009\" title=\"Master suiyuan2009\" class=\"rated-user user-orange\">suiyuan2009</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 13:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146443\" href=\"?#comment-146443\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146443\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49923\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146443\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>problem B,ac automachine is doing the thing that belong to kmp</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146443 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146443 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146443\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146452\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 17:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146452\" href=\"?#comment-146452\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146452\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146452\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div1_E: Should the "Doodler" jump over the platform which H = P ? I just confused about that.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146452 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146452 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146452\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146480\" commentParentId=\"146452\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 11:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146480\" href=\"?#comment-146480\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146452\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146480\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146480\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OK I got the answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146480 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146480 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146480\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146463\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146463\" href=\"?#comment-146463\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146463\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"44\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+44</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146463\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>still waiting for D tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146463 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146463 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146463\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147566\" commentParentId=\"146463\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/05/2013 05:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147566\" href=\"?#comment-147566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146463\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>.. Update .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147566\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"235917\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/saurabhverma\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/143428/avatar/48808a8d5db775d4.jpg'/> </a>\n <div><a href=\"/profile/saurabhverma\" title=\"Expert saurabhverma\" class=\"rated-user user-blue\">saurabhverma</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2015 20:05\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-235917\" href=\"?#comment-235917\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"235917\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"143428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-235917\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In my approach to problem div1 B, I calculated longest common subsequence, prepended virus to it, calculated the Z function and deleted every character which had z[i] >= virus.size(). I don't think my approach is wrong. Can someone tell me if my code is wrong or the approach has some flaw. Thanks. Submission : <a href=\"//codeforces.com/contest/346/submission/11491420\">http://codeforces.com/contest/346/submission/11491420</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-235917 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-235917 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-235917\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"530287\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arpit4427\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/717924/avatar/90dcbc94a1e57cf.jpg'/> </a>\n <div><a href=\"/profile/arpit4427\" title=\"Expert arpit4427\" class=\"rated-user user-blue\">arpit4427</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/26/2019 14:04\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-530287\" href=\"?#comment-530287\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"530287\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"530287\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"717924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-530287\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone explain how to solve this problem <a href=\"/contest/346/problem/B\" title=\"Codeforces Round 201 (Div. 1)\">346B - Lucky Common Subsequence</a>? I have went thorugh the editorial but I could not understand.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-530287 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-530287 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-530287\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8974\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8974 = true;\r\nvar lastPreviewContent8974 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8974] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8974] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:24</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812874998e81759f',t:'MTY5NjcwNTk0NS4wMjkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1754,"cells":{"problem_id":{"kind":"string","value":"347C"},"contest":{"kind":"string","value":"347"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Alice and Bob"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Alice and Bob</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>It is so boring in the summer holiday, isn't it? So Alice and Bob have invented a new game to play. The rules are as follows. First, they get a set of <span class=\"tex-span\"><i>n</i></span> distinct integers. And then they take turns to make the following moves. During each move, either Alice or Bob (the player whose turn is the current) can choose two distinct integers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> from the set, such that the set doesn't contain their absolute difference <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span>. Then this player adds integer <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> to the set (so, the size of the set increases by one).</p><p>If the current player has no valid move, he (or she) loses the game. The question is who will finally win the game if both players play optimally. Remember that Alice always moves first.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 100</span>) — the initial number of elements in the set. The second line contains <span class=\"tex-span\"><i>n</i></span> distinct space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>) — the elements of the set.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single line with the winner's name. If Alice wins print \"<span class=\"tex-font-style-tt\">Alice</span>\", otherwise print \"<span class=\"tex-font-style-tt\">Bob</span>\" (without quotes).</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>2 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Alice<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>5 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Alice<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>5 6 7<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Bob<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first test sample. Alice moves first, and the only move she can do is to choose 2 and 3, then to add 1 to the set. Next Bob moves, there is no valid move anymore, so the winner is Alice.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"bf637a57db6faea465a2f68044366fee\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"f8f8f6cf474a1d90f03554b971b57bc6697e07dd\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='bf637a57db6faea465a2f68044366fee'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F347%2Fproblem%2FC%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='bf637a57db6faea465a2f68044366fee'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/347\">Codeforces Round 201 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='bf637a57db6faea465a2f68044366fee'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/347/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Games, Sprague–Grundy theorem\">\r\n games\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Number theory: Euler function, GCD, divisibility, etc\">\r\n number theory\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1600\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='bf637a57db6faea465a2f68044366fee'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3510\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='bf637a57db6faea465a2f68044366fee'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3510\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8896\" title=\"Codeforces Round #201\" target=\"_blank\">Codeforces Round #201</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1862:1863\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8903\" title=\"Codeforces Round #201 Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1865\" resourceName=\"Codeforces Round #201 Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/347\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/347/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/347/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/347/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/347/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/347/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/347/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/347/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_cf13146a58b106c4d97fa5df3d6957f75035e2e4\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Alice and Bob</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>It is so boring in the summer holiday, isn't it? So Alice and Bob have invented a new game to play. The rules are as follows. First, they get a set of <span class=\"tex-span\"><i>n</i></span> distinct integers. And then they take turns to make the following moves. During each move, either Alice or Bob (the player whose turn is the current) can choose two distinct integers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> from the set, such that the set doesn't contain their absolute difference <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span>. Then this player adds integer <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> to the set (so, the size of the set increases by one).</p><p>If the current player has no valid move, he (or she) loses the game. The question is who will finally win the game if both players play optimally. Remember that Alice always moves first.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 100</span>) — the initial number of elements in the set. The second line contains <span class=\"tex-span\"><i>n</i></span> distinct space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>) — the elements of the set.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single line with the winner's name. If Alice wins print "<span class=\"tex-font-style-tt\">Alice</span>", otherwise print "<span class=\"tex-font-style-tt\">Bob</span>" (without quotes).</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />2 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Alice<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />5 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Alice<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />5 6 7<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>Bob<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first test sample. Alice moves first, and the only move she can do is to choose 2 and 3, then to add 1 to the set. Next Bob moves, there is no valid move anymore, so the winner is Alice.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:56</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122bdfd4dcd4989',t:'MTY5NjY0NjAzNi4xMzEwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Games, Sprague\\u2013Grundy theorem\", \"Mathematics including integration, differential equations, etc\", \"Number theory: Euler function, GCD, divisibility, etc\"]"},"short_tags":{"kind":"string","value":"[\"games\", \"math\", \"number theory\", \"*1600\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8903"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"1c88316eb9ff5851524d80ea59ef3f32\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #201 Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #201 Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='1c88316eb9ff5851524d80ea59ef3f32'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8903\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/MinakoKojima\">MinakoKojima</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/MinakoKojima\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/MinakoKojima\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/MinakoKojima\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/MinakoKojima\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/MinakoKojima\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/MinakoKojima\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/MinakoKojima\" style=\"text-decoration:none;color:black !important;\">MinakoKojima's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8958\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8903\"> <p>Codeforces Round #201 Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a>,\r\n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><img alt=\" \" src=\"/predownloaded/41/3f/413f7303374a112dddc1e63e29cfc12924514cd7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><h1>Overview</h1><p>In DIV 1, there are 4 interesting problems together with a normal one. We think it is reasonable because we can't have a round fullly with intelligence. Problem A, C have weak pretests while others intended to be strong. About more then 200 participants solve A in the early 45mins, then a few of them start from C while most of the other start from B. </p><p>Problem B is a rather standard problem, but if you're unfamiliar with the algorithm, it can be very hard. Problem C is a more intersting problem. As the name implies, there was <a href=\"//codeforces.com/problemset/problem/251/C\">a similar version</a> in the previous round before, but this time it has a brand new constrains.(So here we have a psychology experiment: could different constrains make people thinking in a slightly different way?ww)</p><p>The standard solution of problem C is <span class=\"tex-span\"><i>O</i>((<i>b</i> - <i>a</i>) + <i>nlogn</i>)</span>. The first expected correct solution was written by <a class=\"rated-user user-orange\" href=\"/profile/zeliboba\" title=\"International Master zeliboba\">zeliboba</a>. <a href=\"//codeforces.com/contest/346/submission/4512654\">http://codeforces.com/contest/346/submission/4512654</a></p><p>After that, some people start to solve problem D. Problem D looks like a hard dp problem on a graph at the first glance, the key point is how to avoid the circle in the transfer equation. It turn out to be elegant after you could found a right order of the evaluation. Problem E is challenging which you need find a way to transform the original question into a smaller scale, and cut off many many corner cases ... And in the very end, you find a way like binary search to get <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span> as the time complexity. No one manage to solve problem E during the contest, maybe <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> is the man who closest to it.</p><p>The winner comes to <a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"Grandmaster cgy4ever\">cgy4ever</a>, because he found the draw-black in his previous C submission during the very beginning even when there is nobody hack him! He resubmit it decisively and get back when finished problem D. After that, he use the same trick which made him failed before to hack others and got a handsomely rewards. The second place went to <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a>, because of the combination of decent speed in A, B, C, D.</p><p>Problem B belongs to me, problem C belongs to <a class=\"rated-user user-violet\" href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\">CMHJT</a> and others belong to <a class=\"rated-user user-orange\" href=\"/profile/UESTC_Nocturne\" title=\"International Master UESTC_Nocturne\">UESTC_Nocturne</a>. The illustrator of problem C is <a href=\"http://www.pixiv.net/member_illust.php?mode=medium&illust_id=38602657\">Chairman Miao(貓主席)</a>.</p><h1>Editorial</h1><h3><a href=\"//codeforces.com/problemset/problem/346/A\">Problem A. Alice and Bob</a></h3><h4>Brief description:</h4><p>Alice and Bob play a game, the rules are as follows: First, they will get a set of <span class=\"tex-span\"><i>n</i></span> distinct numbers. And then they take turns to do the following operations. During each operation, either Alice or Bob can choose two different numbers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> from the set, as long as <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> is not in the set, then they add it to the set. The person who can not choose two numbers successfully will lose the game. The question is who will finally win the game if both of them do operations optimally. Remember that Alice always goes first.</p><h4>Analysis:</h4><p>First, no matter what happend, the number set we get at the very endding will be same all the time. Let's say <span class=\"tex-span\"><i>d</i> = <i>gcd</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}. Then the set in the endding will be some things like {<span class=\"tex-span\"><i>d</i></span>, <span class=\"tex-span\">2<i>d</i></span>, <span class=\"tex-span\">3<i>d</i></span>, ... <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}}. So there is always <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub>} / <i>d</i></span> — <span class=\"tex-span\"><i>n</i></span> rounds. And what we should do rest is to check the parity of this value.</p><h3><a href=\"//codeforces.com/problemset/problem/346/B\">Problem B. Lucky Common Subsequence</a></h3><h4>Brief description:</h4><p>You have been given two strings <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and <span class=\"tex-span\"><i>virus</i></span>, and you have to find the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> without <span class=\"tex-span\"><i>virus</i></span> as a substring.</p><h4>Analysis:</h4><p>This is a rather classical problem, let's say if there is no virus, then it is the classical **LCS ** problem. You can solve this by a <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> dynamic programing.</p><p>When consider about the virus, we should add 1 more dimension on the state to trace the growth of the virus. It can be done by wheather <strong>Aho-Corasick automation</strong>, or <strong>KMP</strong> when there is only one virus in this case. The overall time complexity is <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">3</sup>)</span>.</p><h3><a href=\"//codeforces.com/problemset/problem/346/C\">Problem C. Number Transformation II</a></h3><h4>Brief description:</h4><p>You have a number <span class=\"tex-span\"><i>b</i></span>, and want to minus it to <span class=\"tex-span\"><i>a</i></span>, what you can do in each step is weather subtract 1 or <span class=\"tex-span\"><i>b</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> from <span class=\"tex-span\"><i>b</i></span>. And we ask what is the minimum number of steps you need.</p><h4>Analysis:</h4><p>I bet there is a few people know the greedy method even if he/she have solved the early version before.</p><p><a href=\"//codeforces.com/problemset/problem/251/C\">Codeforces #153 Div 1. Problem C. Number Transformation</a></p><p>Let dp[k] denotes the minimum number of steps to transform b+k to b. In each step, you could only choose i which makes b+k-(b+k) mod x[i] minimal to calc dp[k]. It works bacause dp[0..k-1] is a monotone increasing function. Proof: - Say dp[k]=dp[k-t]+1.If t==1, then dp[0..k] is monotone increasing obviously.Otherwise dp[k-1]<=dp[k-t]+1=dp[k] (there must exist a x[i] makes b+k-1 also transform to b+k-t,and it is not necessarily the optimal decision of dp[k-1]). So dp[k] is a monotone increasing function, we can greedily calc dp[a-b].</p><p>In the first glance, it looks like something which will run in square complexity. But actually is linear. That is because, we could cut exactly max{<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>} in each 2 step. It can be proof by induction.</p><p>So the remians work is to delete those same <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>, and watch out some situation could cause degeneration. Many of us failed in this last step and got <strong>TLE</strong></p><h3><a href=\"//codeforces.com/problemset/problem/346/D\">Problem D. Robot Control</a></h3><p>Let's dp from t to s.</p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>Here dp[u] means, the minimum number of orders mzry1992 needs to send in the worst case. The left-hand-side is sending order while the right-hand side is not. At the beginning, we have dp[t] = 1, and dp[s] will be the answer.</p><p>We can see there is circular dependence in this equation, in this situation, one standard method is using Bellman-Ford algorithm to evaluate the dp function.</p><p>But it is not appropriate for this problem.</p><p>(In fact, we add a part of targeted datas in pretest, these datas are enough to block most of our <a href=\"https://en.wikipedia.org/wiki/Bellman%E2%80%93Ford_algorithm\">Bellman-Ford algorithm</a>, although there is still a few participator can get accepted by Bellman-Ford algorithm during the contest.</p><p>Check <a class=\"rated-user user-violet\" href=\"/profile/rares.buhai\" title=\"Candidate Master rares.buhai\">rares.buhai</a>'s <a href=\"//codeforces.com/contest/346/submission/4520171\">solution</a></p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>The expected solution is evaluating the dp function as the increased value of dp[u] itself. Further analysis shows, wheather we decided sending order or not in u can be judged as the out-degree of u.</p> <pre><code><br />while (!Q.empty()) {\n u = Q.front(), Q.pop_front()\n for each edge from v to u\n --out_degree[v]\n\tif (out_degree[v] == 0) {\n relax dp[v] by dp[u]\n if success, add v to the front of Q\n\t}\n\telse{\n\t relax dp[v] by dp[u] + 1\n\t if success, add v to the back of Q\n }\t\n }\n</code></pre><p>Check <a class=\"rated-user user-orange\" href=\"/profile/Ra16bit\" title=\"International Master Ra16bit\">Ra16bit</a>'s <a href=\"//codeforces.com/contest/346/submission/4519668\">solution</a> to see how it works.</p><h3><a href=\"//codeforces.com/problemset/problem/346/E\">Problem E. Doodle Jump</a></h3><h4>Brief description:</h4><p>You have been give <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>, <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>h</i></span> (gcd(<span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>) = 1), For each <span class=\"tex-span\"><i>ai</i></span> mod <span class=\"tex-span\"><i>p</i></span>, (<span class=\"tex-span\"><i>i</i></span>∈[1, n]), check weather the maximum distance in neighborhood after sorting is <= <span class=\"tex-span\"><i>h</i></span>. </p><h4>Analysis:</h4><p>Take <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 for example ... Divided the numbers in group.</p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 18\n</code></pre><p>We start a new group when the number > P</p><p>We found the difference between the elements of the first group is 5, The subsequent is filling some gap between the them ...</p><p>After some observation we could found that we should only consider into one gap ...(e.g. [0, 5] or [15, 20] or [20, 25] ... ) </p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>That says .. <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 is roughly equal to some things in small scale?</p><p>So let's check it in detail. Lemma 1. In any case, the gap after 20 won't better than any gap before it.</p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>For example, in this case, the gap after 20 is: 20, 22 And it has 16 in [15, 17] but no 21. </p><p>Is there any chance that [20, 23] is better than [15, 20]?</p><p>No, that is because, when there is no 21, then (19+5)%23 = 1, go to next floor. and there is no corresponding gap after 20 ([22, 24]) for this gap ([17, 19])</p><p>So we only need to consider [15, 20] ... and we found [15, 20] is roughly equal to [0, 5]</p> <pre><code>e.g. : 15 20 17 19 16 18 \nequal: 0 5 2 4 1 3\n</code></pre><p>we say 'roughly' because we havn't check some boundary case like there is 3 but on 18 ... </p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 \n</code></pre><p>If it happend, we should remove the number 3. .. If we can remove the element 5, then we can from a=5, p=23 to a'=2, p'=5 ...(n' = an/p, a' = a-p%a, if there is 3 but no 18, n'=n'-1)</p><p>The rest things is to discuss wheather 5 is necessary or not.</p><p>Let's we have:</p> <pre><code>0 2 4\n1 3\n</code></pre><p>If the 2*n'<5, then there is only one floor, the answer is max(2, 5-2*n'). If there is more than one floor, we could conclude that 5 is useless.</p><p>Proof: Elemets in 1st floor is: </p> <pre><code>0 a 2a 3a ...\n</code></pre><p>Let's say the maximum elements in 1st floor is x, then the minimum element in the 2nd floor is b0 = x+a-p, because b0 — a = x-p, so the difference between b0 and a is equal to the difference between x and p. That is, we can consider [b0, a] rather than [x, p], when there is a element insert in [b0, a], there must be some element insert in [x, p] in the same position.</p><p>So we have have succeeded to transform our original problem into a small one. Of couse, this problem havn't been solved, we haven't consider the time complexity. Says a' = a — p%a, when p = a+1, then a' = a-1, but we have <span class=\"tex-span\"><i>a</i></span> equal to 10^9, it won't work.</p><p>But, let's we have A1, A2, ... An ... and we subtract <span class=\"tex-span\"><i>d</i></span> from all of them, the answer won't be changed. So we can use p%a substitute for a-p%a, this is equivalent to we subtract %p% from all of them ...</p><p>So we set a' = min(a-p%a, p%a), so a'<=a/2, therefore, the final time complexity is <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span>.</p><p>You can check <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> <a href=\"//codeforces.com/contest/346/submission/4523388\">'s solution</a> for detail.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/346\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/347\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-4906-8958\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"4906\",\n blogEntryId: \"8903\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+56</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/MinakoKojima\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/MinakoKojima\">\n MinakoKojima\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8903#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8903#comments\">\n 66\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8974\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (56)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146290\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mohammadrdeh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/47/avatar/91eee3f7a5ec41f6.jpg'/> </a>\n <div><a href=\"/profile/mohammadrdeh\" title=\"Specialist mohammadrdeh\" class=\"rated-user user-cyan\">mohammadrdeh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146290\" href=\"?#comment-146290\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146290\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"14\"\r\n data-commentUserId=\"47\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+14</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146290\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>there is a typo: "... the classical <strong>LCA</strong> problem ..." => <strong>LCS</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146290 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146290 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146290\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146291\" commentParentId=\"146290\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146291\" href=\"?#comment-146291\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146290\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146291\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146291\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you. Fixed. m(_ _)m</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146291 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146291 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146291\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146297\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 05:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146297\" href=\"?#comment-146297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Actually our standard solution to C is O(b-a+n). O(b-a+n),O(b-a+nlogn),O((b-a+n)logn) are all able to pass during the test.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146297\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146335\" commentParentId=\"146297\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mmaxio\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/486/avatar/4bb53c24fc9e4c1.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/mmaxio\" title=\"International Master mmaxio\" class=\"rated-user user-orange\">mmaxio</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 17:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146335\" href=\"?#comment-146335\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146297\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146335\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146335\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"486\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146335\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>oh, never mind</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146335 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146335 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146335\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146299\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shashwat.gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6204/avatar/67f8e17c53f70578.jpg'/> </a>\n <div><a href=\"/profile/shashwat.gupta\" title=\"Specialist shashwat.gupta\" class=\"rated-user user-cyan\">shashwat.gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146299\" href=\"?#comment-146299\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146299\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"6204\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146299\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Problem B: Can you Explain little bit more on How "Aho-Corasick automation, or KMP" can help in figuring out smallest string that does not contain virus.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146299 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146299 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146299\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146300\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146300\" href=\"?#comment-146300\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146300\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146300\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For B, I already had the intuitive idea that this problem will be solved by either Aho-Corasick algorithm or KMP with dp, but I could not formalize the idea of states transition in dp. Could you please just provide the state in your dp algorithm?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146300 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146300 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146300\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146354\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146354\" href=\"?#comment-146354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146354\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Original problem can be solved by dp with two parameters DP[Len(s)] [Len(t)]. <a href=\"https://en.wikipedia.org/wiki/Longest_common_subsequence_problem\">http://en.wikipedia.org/wiki/Longest_common_subsequence_problem</a></p><p>To solve B you need to modificate it to DP[Len(s)][Len(t)][Len(virus)-1] where third parameter means maximum length of suffix of LCS that equal to prefix of virus.</p><p>To easy check where we go from K state (third parameter) by character C we can make automat on prefix function by virus.</p><p>Then if we stand in DP[i][j][k] :<br /> 1) if(s[i] == t[j] and Automat[k][c]<Len(virus) we try to relax DP[i+1][j+1][Automat[k][c]]<br /> 2) Try to relax DP[i][j+1][k] and DP[i+1][j][k]</p><p><strong>UPD</strong> My solution: <a href=\"//codeforces.com/contest/346/submission/4532899\">http://codeforces.com/contest/346/submission/4532899</a> (hope it understandable)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146354\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146357\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146357\" href=\"?#comment-146357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>got it, many thanks to you man :) Also understood why KMP tag mentioned in the problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146357\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146493\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lama\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/72190/avatar/735906a91d1576e3.jpg'/> </a>\n <div><a href=\"/profile/lama\" title=\"Expert lama\" class=\"rated-user user-blue\">lama</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 18:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146493\" href=\"?#comment-146493\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146493\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146493\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) Can you please explain what "maximum length of suffix of LCS that equal to prefix of virus" means? 2) What is an automat?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146493 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146493 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146493\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146519\" commentParentId=\"146493\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/25/2013 05:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146519\" href=\"?#comment-146519\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146493\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146519\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146519\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146519\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) We stand in DP[i][j][k]-state (in which we store longest LCS), virus = "virus" <br /> Let's go from k = 0 to 4,then:</p> <pre><code>0) DP[i][j][0] means that finded LCS not ends on "v" or "vi" or "vir" or "viru" or "virus". (example: "a")\n\n1) DP[i][j][1] means that finded LCS ends on "v", but not on "vi" or "vir" or "viru" or "virus". (example: "av")\n\n2) DP[i][j][2] means that finded LCS ends on "vi", but not on "vir" or "viru" or "virus". (example: "avi")\t\n\n3) DP[i][j][3] means that finded LCS ends on "vir", but not on "viru" or "virus". (example: "avir")\n\n4) DP[i][j][4] means that finded LCS ends on "viru", but not on "virus". (example: "aviru")\n\nWe take "longest suffix of LCS that equal prefix of virus", because virus could be: "vvvvv" or "ababv" (and infinite others)\n If LCS = "avvv" - it ends on "v","vv","vvv". (virus = "vvvvv")\n If LCS = "aabab" - it ends on "ab" and "abab". (virus = "ababv")\n</code></pre><p><a href=\"https://en.wikipedia.org/wiki/Knuth%E2%80%93Morris%E2%80%93Pratt_algorithm\">KMP</a></p><p>2) <a href=\"https://en.wikipedia.org/wiki/Automata_theory\">http://en.wikipedia.org/wiki/Automata_theory</a></p><p>Can't find nothing about automaton on prefix-function in english. I hope you will be able understand <a href=\"http://e-maxx.ru/algo/prefix_function\">this</a> with some translator (google translate for example).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146519 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146519 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146519\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"551712\" commentParentId=\"146519\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/srv_twry\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/447741/avatar/d1a80b00eb029c2b.jpg'/> </a>\n <div><a href=\"/profile/srv_twry\" title=\"Expert srv_twry\" class=\"rated-user user-blue\">srv_twry</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/19/2019 12:58\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-551712\" href=\"?#comment-551712\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146519\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"551712\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"447741\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-551712\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Fortunately, the e-maxx article on Prefix function has been translated in English and can be found here: <a href=\"https://cp-algorithms.com/string/prefix-function.html#toc-tgt-12\">prefix-function: automaton on prefix-function</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-551712 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-551712 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-551712\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"768401\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ttbbnnn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1694563/avatar/ff85df0301cf6f76.jpg'/> </a>\n <div><a href=\"/profile/ttbbnnn\" title=\"Master ttbbnnn\" class=\"rated-user user-orange\">ttbbnnn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2021 20:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-768401\" href=\"?#comment-768401\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"768401\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1694563\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-768401\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My solution for B got a WA on test 41 and I don't know why :<, please help me with this code: <a href=\"https://codeforces.com/contest/346/submission/109283664\">https://codeforces.com/contest/346/submission/109283664</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-768401 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-768401 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-768401\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146301\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146301\" href=\"?#comment-146301\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146301\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146301\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146301\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"So the remians work is to delete those same xi, and watch out some situation could cause degeneration. Many of us failed in this last step and got TLE", I really could not understand this. What you you mean by degeneration in this case? Please explain this last important step.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146301 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146301 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146301\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146302\" commentParentId=\"146301\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:37\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146302\" href=\"?#comment-146302\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146301\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146302\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146302\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>suppose b=1, all x[i]>a, what will happen?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146302 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146302 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146302\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146304\" commentParentId=\"146302\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146304\" href=\"?#comment-146304\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146302\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146304\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146304\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As b = 1, All x[i] > a. Then a % x[i] = a. So if we take this, then we will lead to a — a = 0, which is less than b. So we need to move one by one, so answer would be a.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146304 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146304 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146304\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146309\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146309\" href=\"?#comment-146309\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146309\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146309\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Alice and Bob problem how do you prove that you will always get {d, 2d, 3d, ... max{xi}} in the end. It is easy to see but I am unable to prove it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146309 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146309 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146309\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146365\" commentParentId=\"146309\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marat.snowbear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98082/avatar/1499cf6d0c86172.jpg'/> </a>\n <div><a href=\"/profile/marat.snowbear\" title=\"International Master marat.snowbear\" class=\"rated-user user-orange\">marat.snowbear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146365\" href=\"?#comment-146365\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146309\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146365\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"98082\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146365\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I convinced myself like this:</p> <ol> <li>Prove that we will be able to get d by some sequence of subtractions.</li> <li>Prove that we will be able to generate {d, 2d, 3d, ...}</li> <li>Prove that we will not be able to get anything else except for { d, 2d, 3d, ... }</li> </ol><p>In details:</p> <ol> <li><p>See <a href=\"https://en.wikipedia.org/wiki/Euclidean_algorithm\">Euclidean algorithm for finding GCD</a>. If you will look into the description or code you will see that it does exactly what is asked in this problem — subtracts numbers one from another. And the result is GCD of original two numbers. So you can see that by some sequence of subtractions you can get GCD.</p></li> <li><p>If you already have d which GCD of all the numbers then you can easily fill all the gaps in { d, 2d, 3d, ..., max } sequence by starting subtracting d from { max, max — d, max — 2d, ... }. So you will get the intended set.</p></li> <li><p>You cannot subtract two numbers a and b which have GCD(a, b) = d and get result which won't be dividable by d. So if you start with set where every numbers can be divided by d then no matter what you subtract you will always have the result which is also dividable by d.</p></li> </ol></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146365 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146365 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146365\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146390\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 16:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146390\" href=\"?#comment-146390\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146390\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146390\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, got it. Thanks!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146390 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146390 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146390\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"774539\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/25/2021 20:24\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-774539\" href=\"?#comment-774539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"774539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-774539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-774539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-774539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-774539\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146310\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i_coder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i_coder\" title=\"Expert i_coder\" class=\"rated-user user-blue\">i_coder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146310\" href=\"?#comment-146310\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146310\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"41979\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146310\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Is this the final editorial (except the D problem) ? The explanations to problems B and C are very limited and not at all well elaborated.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146310 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146310 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146310\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146314\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146314\" href=\"?#comment-146314\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146314\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146314\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can you tell me that why the number of rounds in Problem A will be max(xi)/d-n ? How do you come to this point ? can you please tell me this as am not to figure out this thing ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146314 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146314 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146314\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146316\" commentParentId=\"146314\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:45\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146316\" href=\"?#comment-146316\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146314\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146316\" revisionCount=\"7\" revision=\"7\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">7</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146316\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146316\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>take example <br /> 3 9 54 <br /> gcd (3, 9, 54) = 3 <br /> Now total rounds possible including (3, 9, 54) =<br />all multiples of 3 upto 54 <br /> 3, 6, 9, 12, 15, 18 ... 54 <br /> </p><p>So total count of these numbers = 54 / 3 = 18. <br /> </p><p>Now as out of these numbers 3 numbers are already taken, so subtract 3 <br /> so rounds remaining = 18 — 3 = 15 </p><p>Now it is very easy to generalize for 3 being d and 54 being n</p><p>answer would be n / d — n. <br /> I hope it is clear now :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146316 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146316 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146316\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146319\" commentParentId=\"146316\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146319\" href=\"?#comment-146319\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146316\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146319\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146319\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes, it is more clear to me now. but one thing is that how did you approach to gcd thing ? I understood the problem, the logic and all. how did you approach that it will be done using gcd thing and all ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146319 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146319 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146319\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146322\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146322\" href=\"?#comment-146322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146322\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My Ideas during solving the problem: <br /> all the examples had gcd 1. So I directly thought answer as max(xi) — n. <br /> But I thought it can not be too simple, I need to think more. <br /> So I took a case 2 4 6, I immediately found I am wrong in this case. <br /> Then the idea came into mind that if gcd of numbers is g. then we can not create any number not divisible by g because (g *k1 — k * k2) = g * (k1 — k2). </p><p>So Finally I coded it and got accpeted :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146322\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146338\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 19:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146338\" href=\"?#comment-146338\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146338\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146338\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>given the numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>, what is the minimum positive value you can achieve by combining them? </p><p>Let's write down the equation: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>·<i>x</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub>·<i>x</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>n</i></sub>·<i>x</i><sub class=\"lower-index\"><i>n</i></sub> = <i>d</i></span>, where <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> are some unknown integers. </p><p>It is, as you can see, none other than linear Diophantine equation. And it is known there is no solutions if <span class=\"tex-span\"><i>d</i></span> is not a multiple of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span> </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146338 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146338 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146338\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146317\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/subway\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123924/avatar/706e86f587cbabf0.jpg'/> </a>\n <div><a href=\"/profile/subway\" title=\"Expert subway\" class=\"rated-user user-blue\">subway</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146317\" href=\"?#comment-146317\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146317\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146317\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@hellodear-the final set will contain all elements {d,2d,3d,..max(Xi)} (d=gcd of all elements) so total no. of elements in final set =max(Xi)/d since initially we have 'n' elements total no. of new elements to be added in set to make it complete=(max(Xi)/d)-n.. hope this helps you..:)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146317 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146317 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146317\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146320\" commentParentId=\"146317\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146320\" href=\"?#comment-146320\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146317\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146320\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146320\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in this thing, I was applying some game theory, but it doesn't include anything like that. when the question says optimally, then how do you form examples so as to test your code on them ? because optimally means in the best they can. can you elaborate ? thanks to you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146320 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146320 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146320\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146324\" commentParentId=\"146320\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146324\" href=\"?#comment-146324\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146320\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146324\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146324\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146324\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>optimality argument is simple and also given in the editorial itself. <br /> As total you numbers finally would be {d, 2 * d,, .,, max (xi)}. <br /> Hence whatever you add to the these set, no other person will be able to add that as he has to add a new number everytime to this test. <br /> So outcome depend on the parity of turns.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146324 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146324 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146324\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146325\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sinamosavi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/87557/avatar/bde58fa97bcc5eb0.jpg'/> </a>\n <div><a href=\"/profile/sinamosavi\" title=\"Pupil sinamosavi\" class=\"rated-user user-green\">sinamosavi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146325\" href=\"?#comment-146325\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146325\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"87557\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146325\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the complete proof for A.Div1 is not that much straightforward. Maybe I'm making it too much difficult, but this is my complete proof:</p><p>First by induction, we prove that the numbers in the end will be <span class=\"tex-span\"><i>a</i>, 2<i>a</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Let <span class=\"tex-span\"><i>g</i> = <i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ... , <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span>. It's trivial that in the end <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>. Assume that <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>, because our numbers will be <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), 2<i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>, so we would have a new gcd. That's a contradiction, so <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) = <i>g</i></span> and our numbers will be <span class=\"tex-span\"><i>g</i>, 2<i>g</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Each move adds one number and in the end there will be <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e6ac12549498d8aaad3d63270d12497bc74a9f84.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> numbers, so the answer wil be the parity of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/48ba1bfd0fa315ab1595947b8e046b4cc211b908.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Sorry for my bad English.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146325 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146325 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146325\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146332\" commentParentId=\"146325\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146332\" href=\"?#comment-146332\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146325\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146332\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-13\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146332\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What about this test <code>2 3 5</code>? <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≠ <i>gcd</i></span></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146332 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146332 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146332\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146333\" commentParentId=\"146332\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146333\" href=\"?#comment-146333\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146332\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146333\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146333\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Oops. You've meant that <span class=\"tex-span\"><i>a</i></span> — is the result. Sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146333 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146333 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146333\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146334\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 16:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146334\" href=\"?#comment-146334\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146334\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146334\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146334\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>But how to prove that there is always a way to choose <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> while the number of the current round less than the maximum number of rounds? (Div2C)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146334 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146334 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146334\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146339\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:22\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146339\" href=\"?#comment-146339\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146339\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146339\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146339\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If gcd{xi}＝1, then for every xi there must exist ti to make sum｛xi*ti｝＝1. </p><p>(For example, x1＝5,x2＝7,then t1＝3,t2＝-2.x1*t1＋x2*t2＝1.)</p><p>And sum{xi*ti} can be performed in a few turns. ( (5-(7-5))-(7-5). )</p><p>And if we can get 1, then what number between [1,max{xi}] can't we get？</p><p>if gcd{xi}≠1.the proof is similar.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146339 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146339 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146339\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146341\" commentParentId=\"146339\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146341\" href=\"?#comment-146341\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146339\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146341\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146341\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why there is must exist such t[i]?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146341 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146341 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146341\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146366\" commentParentId=\"146341\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146366\" href=\"?#comment-146366\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146341\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146366\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146366\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You must know if gcd(a,b)＝1, there must exist x and y to make ax＋by＝1. It can be proved from this.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146366 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146366 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146366\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146376\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146376\" href=\"?#comment-146376\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146376\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146376\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146376\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So.. If we divide all the numbers by GCD, and after that a pair of coprime numbers have appeared, we always can reach 1. Let's choose coprime <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, then <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> will be also coprime with <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, and it will be less then <span class=\"tex-span\"><i>max</i>(<i>x</i>, <i>y</i>)</span>. So we can choose <span class=\"tex-span\"><i>mid</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>x</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>min</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>y</i><sub class=\"lower-index\">1</sub></span>, and they are coprime, and <span class=\"tex-span\">|<i>x</i><sub class=\"lower-index\">1</sub> - <i>y</i><sub class=\"lower-index\">1</sub>|</span> will be less than <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>. And etc. by induction. But what to do if there is not a pair of coprime numbers after dividing by GCD? For example <code>35 45 63</code>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146376 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146376 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146376\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146404\" commentParentId=\"146376\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146404\" href=\"?#comment-146404\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146376\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146404\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146404\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146404\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>63*2＋45*5＋35*(-10)＝1</p><p>Because gcd (35,45)＝5, we can consider 35 and 45 as one number 5x. Because gcd(5,63)＝1, so there must exist x,y to make 5x＋63y＝1.</p><p>So here comes a tragedy. We can get 5 first. Then we use this number together with 63 to make 1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146404 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146404 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146404\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146346\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KiAsaGibona\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/KiAsaGibona\" title=\"Specialist KiAsaGibona\" class=\"rated-user user-cyan\">KiAsaGibona</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 21:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146346\" href=\"?#comment-146346\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146346\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146346\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"99053\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146346\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Someone please explain the greedy idea of (Div 1 C) (Number Transformation II). Thanks in advance :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146346 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146346 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146346\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146367\" commentParentId=\"146346\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 09:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146367\" href=\"?#comment-146367\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146346\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146367\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146367\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's a pretty simple greedy idea: Just pick the <code>x</code> that makes the value of <code>a</code> smallest after applying the operation <code>a = a - a%x</code> (or subtract 1 if no choice for <code>x</code> makes <code>a</code> smaller). The proof why this works is given in the editorial: it is never better to get a larger number, so you should get the smallest one you can.</p><p>As listed on the last paragraph of the editorial you have to be careful to remove all <code>x</code> that are either duplicates or cannot be used anymore (<code>a - (a%x)</code> is smaller than <code>b</code>), otherwise you will get TLE.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146367 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146367 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146367\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146382\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146382\" href=\"?#comment-146382\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146382\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146382\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146382\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>how to find this x for each number?</p><p>we will iterate on all x[i]s and only delete x[i]s when x[i] > a?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146382 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146382 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146382\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146405\" commentParentId=\"146382\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146405\" href=\"?#comment-146405\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146382\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146405\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146405\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Iterate through all x[i]s and delete them when a — (a%x[i]) is smaller than b (if you only delete when x[i] > a, you will also get TLE).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146405 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146405 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146405\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146625\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 17:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146625\" href=\"?#comment-146625\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146625\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146625\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm really striving to understand why the algorithm turns out to be linear instead of quadratic... I know the editorial says "That is because, we could cut exactly <span class=\"tex-span\"><i>max</i>{<i>xi</i>}</span> in each 2 step.", but I can't really get what it means :\\</p><p>Can you give me a hint? Thanks :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146625 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146625 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146625\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146643\" commentParentId=\"146625\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/xenoslash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88090/avatar/f75f8cbc20d6133f.jpg'/> </a>\n <div><a href=\"/profile/xenoslash\" title=\"Expert xenoslash\" class=\"rated-user user-blue\">xenoslash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 19:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146643\" href=\"?#comment-146643\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146625\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146643\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146643\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"88090\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146643\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have an easy intuition of cutting at least max{xi} in O(1) steps, not sure what was the intended 2 step proofs though. I am going to use xi to refer to max{xi}, and assume that proper care is taken to only keep the relevant xi's.</p><p>When we do a-(a % xi), we bring caused a to be the next largest integer <= a that is a multiple of xi, since now new_a % xi = 0. Then, if a is divisible by xi, you can do.., do a-1 (causing it to be non-divisible by xi), then finally a-(a%xi) again. In this 3 step sequence you have brought a down to the next lower multiple of xi, and have essentially cut max{xi} in O(1) number of steps.</p><p>Sample code : <a href=\"//codeforces.com/contest/346/submission/4545367\">http://codeforces.com/contest/346/submission/4545367</a> Yeah I used tree set so it's not exactly O(n).. but hash set keeps giving me TLE :(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146643 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146643 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146643\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146689\" commentParentId=\"146643\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2013 12:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146689\" href=\"?#comment-146689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146643\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you very much, that was really eye-opening! This is why I love Codeforces, great community! :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146689\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146371\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Corvo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/11909/avatar/8404ac1aff5270ec.jpg'/> </a>\n <div><a href=\"/profile/Corvo\" title=\"Pupil Corvo\" class=\"rated-user user-green\">Corvo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 12:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146371\" href=\"?#comment-146371\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146371\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"11909\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146371\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please explain why the problem is solved through the GDC (A)? I tried like <a href=\"https://codeforces.com/contest/347/submission/4535232\">this</a>, but I still can not understand why you can not do. Please give a short test on which the decision falls. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146371 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146371 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146371\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146375\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146375\" href=\"?#comment-146375\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146375\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146375\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><pre><code>3\n14 4 2\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146375 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146375 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146375\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146378\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akashdeep\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/39866/avatar/6f66d1bbe26ef4ca.jpg'/> </a>\n <div><a href=\"/profile/akashdeep\" title=\"International Master akashdeep\" class=\"rated-user user-orange\">akashdeep</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146378\" href=\"?#comment-146378\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146378\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"39866\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146378\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Because only those numbers are possible in the game which are multiple of gcd. See this simplest test case</p> <pre><code>2\n4 6\n</code></pre><p>The only number possible in the game is (6-4) i.e. 2, but in your code u are assuming that somehow these (1,2,3,5) numbers can be obtained which is a wrong assumption.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146378 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146378 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146378\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146408\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/NegaTeeF\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/NegaTeeF\" title=\"Master NegaTeeF\" class=\"rated-user user-orange\">NegaTeeF</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 20:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146408\" href=\"?#comment-146408\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146408\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"65829\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146408\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Explain please, how to do Div1-D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146408 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146408 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146408\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146410\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/irakli_p\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29034/avatar/d879a3156498c6c7.jpg'/> </a>\n <div><a href=\"/profile/irakli_p\" title=\"Expert irakli_p\" class=\"rated-user user-blue\">irakli_p</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 21:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146410\" href=\"?#comment-146410\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146410\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29034\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146410\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i didn't understand Div 2 — D can someone explain it to me please </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146410 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146410 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146410\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146443\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/suiyuan2009\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49923/avatar/9065a92c0b30b883.jpg'/> </a>\n <div><a href=\"/profile/suiyuan2009\" title=\"Master suiyuan2009\" class=\"rated-user user-orange\">suiyuan2009</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 13:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146443\" href=\"?#comment-146443\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146443\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49923\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146443\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>problem B,ac automachine is doing the thing that belong to kmp</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146443 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146443 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146443\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146452\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 17:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146452\" href=\"?#comment-146452\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146452\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146452\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div1_E: Should the "Doodler" jump over the platform which H = P ? I just confused about that.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146452 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146452 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146452\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146480\" commentParentId=\"146452\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 11:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146480\" href=\"?#comment-146480\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146452\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146480\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146480\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OK I got the answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146480 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146480 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146480\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146463\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146463\" href=\"?#comment-146463\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146463\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"44\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+44</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146463\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>still waiting for D tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146463 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146463 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146463\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147566\" commentParentId=\"146463\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/05/2013 05:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147566\" href=\"?#comment-147566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146463\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>.. Update .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147566\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"235917\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/saurabhverma\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/143428/avatar/48808a8d5db775d4.jpg'/> </a>\n <div><a href=\"/profile/saurabhverma\" title=\"Expert saurabhverma\" class=\"rated-user user-blue\">saurabhverma</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2015 20:05\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-235917\" href=\"?#comment-235917\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"235917\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"143428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-235917\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In my approach to problem div1 B, I calculated longest common subsequence, prepended virus to it, calculated the Z function and deleted every character which had z[i] >= virus.size(). I don't think my approach is wrong. Can someone tell me if my code is wrong or the approach has some flaw. Thanks. Submission : <a href=\"//codeforces.com/contest/346/submission/11491420\">http://codeforces.com/contest/346/submission/11491420</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-235917 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-235917 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-235917\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"530287\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arpit4427\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/717924/avatar/90dcbc94a1e57cf.jpg'/> </a>\n <div><a href=\"/profile/arpit4427\" title=\"Expert arpit4427\" class=\"rated-user user-blue\">arpit4427</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/26/2019 14:04\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-530287\" href=\"?#comment-530287\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"530287\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"530287\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"717924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-530287\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone explain how to solve this problem <a href=\"/contest/346/problem/B\" title=\"Codeforces Round 201 (Div. 1)\">346B - Lucky Common Subsequence</a>? I have went thorugh the editorial but I could not understand.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-530287 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-530287 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-530287\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8974\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8974 = true;\r\nvar lastPreviewContent8974 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8974] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8974] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:24</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812874998e81759f',t:'MTY5NjcwNTk0NS4wMjkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1755,"cells":{"problem_id":{"kind":"string","value":"347D"},"contest":{"kind":"string","value":"347"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Lucky Common Subsequence"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Lucky Common Subsequence</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>3 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>512 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>In mathematics, a <span class=\"tex-font-style-it\">subsequence</span> is a sequence that can be derived from another sequence by deleting some elements without changing the order of the remaining elements. For example, the sequence <span class=\"tex-font-style-tt\">BDF</span> is a subsequence of <span class=\"tex-font-style-tt\">ABCDEF</span>. A <span class=\"tex-font-style-it\">substring</span> of a string is a continuous subsequence of the string. For example, <span class=\"tex-font-style-tt\">BCD</span> is a substring of <span class=\"tex-font-style-tt\">ABCDEF</span>.</p><p>You are given two strings <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and another string called <span class=\"tex-span\"><i>virus</i></span>. Your task is to find the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span>, such that it doesn't contain <span class=\"tex-span\"><i>virus</i></span> as a substring.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input contains three strings in three separate lines: <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and <span class=\"tex-span\"><i>virus</i></span> (<span class=\"tex-span\">1 ≤ |<i>s</i><sub class=\"lower-index\">1</sub>|, |<i>s</i><sub class=\"lower-index\">2</sub>|, |<i>virus</i>| ≤ 100</span>). Each string consists only of uppercase English letters.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> without <span class=\"tex-span\"><i>virus</i></span> as a substring. If there are multiple answers, any of them will be accepted. </p><p>If there is no valid common subsequence, output 0.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>AJKEQSLOBSROFGZ<br/>OVGURWZLWVLUXTH<br/>OZ<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>ORZ<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>AA<br/>A<br/>A<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"5612488faf1b5c77a630567bf5a08f92\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"f8f8f6cf474a1d90f03554b971b57bc6697e07dd\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='5612488faf1b5c77a630567bf5a08f92'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F347%2Fproblem%2FD%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='5612488faf1b5c77a630567bf5a08f92'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/347\">Codeforces Round 201 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='5612488faf1b5c77a630567bf5a08f92'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/347/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Prefix- and Z-functions, suffix structures, Knuth–Morris–Pratt algorithm, etc\">\r\n strings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2000\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='5612488faf1b5c77a630567bf5a08f92'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3511\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='5612488faf1b5c77a630567bf5a08f92'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3511\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8896\" title=\"Codeforces Round #201\" target=\"_blank\">Codeforces Round #201</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1862:1863\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8903\" title=\"Codeforces Round #201 Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1865\" resourceName=\"Codeforces Round #201 Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/347\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/347/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/347/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/347/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/347/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/347/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/347/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/347/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_b633424aa231adba4f1d8a43e903b14bd74fc4de\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Lucky Common Subsequence</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>3 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>512 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>In mathematics, a <span class=\"tex-font-style-it\">subsequence</span> is a sequence that can be derived from another sequence by deleting some elements without changing the order of the remaining elements. For example, the sequence <span class=\"tex-font-style-tt\">BDF</span> is a subsequence of <span class=\"tex-font-style-tt\">ABCDEF</span>. A <span class=\"tex-font-style-it\">substring</span> of a string is a continuous subsequence of the string. For example, <span class=\"tex-font-style-tt\">BCD</span> is a substring of <span class=\"tex-font-style-tt\">ABCDEF</span>.</p><p>You are given two strings <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and another string called <span class=\"tex-span\"><i>virus</i></span>. Your task is to find the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span>, such that it doesn't contain <span class=\"tex-span\"><i>virus</i></span> as a substring.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input contains three strings in three separate lines: <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and <span class=\"tex-span\"><i>virus</i></span> (<span class=\"tex-span\">1 ≤ |<i>s</i><sub class=\"lower-index\">1</sub>|, |<i>s</i><sub class=\"lower-index\">2</sub>|, |<i>virus</i>| ≤ 100</span>). Each string consists only of uppercase English letters.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> without <span class=\"tex-span\"><i>virus</i></span> as a substring. If there are multiple answers, any of them will be accepted. </p><p>If there is no valid common subsequence, output 0.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>AJKEQSLOBSROFGZ<br />OVGURWZLWVLUXTH<br />OZ<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>ORZ<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>AA<br />A<br />A<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:57</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122be057dfd7b4f',t:'MTY5NjY0NjAzNy40MTIwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Dynamic programming\", \"Prefix- and Z-functions, suffix structures, Knuth\\u2013Morris\\u2013Pratt algorithm, etc\"]"},"short_tags":{"kind":"string","value":"[\"dp\", \"strings\", \"*2000\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8903"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"1c88316eb9ff5851524d80ea59ef3f32\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #201 Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #201 Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='1c88316eb9ff5851524d80ea59ef3f32'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8903\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/MinakoKojima\">MinakoKojima</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/MinakoKojima\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/MinakoKojima\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/MinakoKojima\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/MinakoKojima\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/MinakoKojima\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/MinakoKojima\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/MinakoKojima\" style=\"text-decoration:none;color:black !important;\">MinakoKojima's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8958\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8903\"> <p>Codeforces Round #201 Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a>,\r\n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><img alt=\" \" src=\"/predownloaded/41/3f/413f7303374a112dddc1e63e29cfc12924514cd7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><h1>Overview</h1><p>In DIV 1, there are 4 interesting problems together with a normal one. We think it is reasonable because we can't have a round fullly with intelligence. Problem A, C have weak pretests while others intended to be strong. About more then 200 participants solve A in the early 45mins, then a few of them start from C while most of the other start from B. </p><p>Problem B is a rather standard problem, but if you're unfamiliar with the algorithm, it can be very hard. Problem C is a more intersting problem. As the name implies, there was <a href=\"//codeforces.com/problemset/problem/251/C\">a similar version</a> in the previous round before, but this time it has a brand new constrains.(So here we have a psychology experiment: could different constrains make people thinking in a slightly different way?ww)</p><p>The standard solution of problem C is <span class=\"tex-span\"><i>O</i>((<i>b</i> - <i>a</i>) + <i>nlogn</i>)</span>. The first expected correct solution was written by <a class=\"rated-user user-orange\" href=\"/profile/zeliboba\" title=\"International Master zeliboba\">zeliboba</a>. <a href=\"//codeforces.com/contest/346/submission/4512654\">http://codeforces.com/contest/346/submission/4512654</a></p><p>After that, some people start to solve problem D. Problem D looks like a hard dp problem on a graph at the first glance, the key point is how to avoid the circle in the transfer equation. It turn out to be elegant after you could found a right order of the evaluation. Problem E is challenging which you need find a way to transform the original question into a smaller scale, and cut off many many corner cases ... And in the very end, you find a way like binary search to get <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span> as the time complexity. No one manage to solve problem E during the contest, maybe <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> is the man who closest to it.</p><p>The winner comes to <a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"Grandmaster cgy4ever\">cgy4ever</a>, because he found the draw-black in his previous C submission during the very beginning even when there is nobody hack him! He resubmit it decisively and get back when finished problem D. After that, he use the same trick which made him failed before to hack others and got a handsomely rewards. The second place went to <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a>, because of the combination of decent speed in A, B, C, D.</p><p>Problem B belongs to me, problem C belongs to <a class=\"rated-user user-violet\" href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\">CMHJT</a> and others belong to <a class=\"rated-user user-orange\" href=\"/profile/UESTC_Nocturne\" title=\"International Master UESTC_Nocturne\">UESTC_Nocturne</a>. The illustrator of problem C is <a href=\"http://www.pixiv.net/member_illust.php?mode=medium&illust_id=38602657\">Chairman Miao(貓主席)</a>.</p><h1>Editorial</h1><h3><a href=\"//codeforces.com/problemset/problem/346/A\">Problem A. Alice and Bob</a></h3><h4>Brief description:</h4><p>Alice and Bob play a game, the rules are as follows: First, they will get a set of <span class=\"tex-span\"><i>n</i></span> distinct numbers. And then they take turns to do the following operations. During each operation, either Alice or Bob can choose two different numbers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> from the set, as long as <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> is not in the set, then they add it to the set. The person who can not choose two numbers successfully will lose the game. The question is who will finally win the game if both of them do operations optimally. Remember that Alice always goes first.</p><h4>Analysis:</h4><p>First, no matter what happend, the number set we get at the very endding will be same all the time. Let's say <span class=\"tex-span\"><i>d</i> = <i>gcd</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}. Then the set in the endding will be some things like {<span class=\"tex-span\"><i>d</i></span>, <span class=\"tex-span\">2<i>d</i></span>, <span class=\"tex-span\">3<i>d</i></span>, ... <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}}. So there is always <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub>} / <i>d</i></span> — <span class=\"tex-span\"><i>n</i></span> rounds. And what we should do rest is to check the parity of this value.</p><h3><a href=\"//codeforces.com/problemset/problem/346/B\">Problem B. Lucky Common Subsequence</a></h3><h4>Brief description:</h4><p>You have been given two strings <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and <span class=\"tex-span\"><i>virus</i></span>, and you have to find the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> without <span class=\"tex-span\"><i>virus</i></span> as a substring.</p><h4>Analysis:</h4><p>This is a rather classical problem, let's say if there is no virus, then it is the classical **LCS ** problem. You can solve this by a <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> dynamic programing.</p><p>When consider about the virus, we should add 1 more dimension on the state to trace the growth of the virus. It can be done by wheather <strong>Aho-Corasick automation</strong>, or <strong>KMP</strong> when there is only one virus in this case. The overall time complexity is <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">3</sup>)</span>.</p><h3><a href=\"//codeforces.com/problemset/problem/346/C\">Problem C. Number Transformation II</a></h3><h4>Brief description:</h4><p>You have a number <span class=\"tex-span\"><i>b</i></span>, and want to minus it to <span class=\"tex-span\"><i>a</i></span>, what you can do in each step is weather subtract 1 or <span class=\"tex-span\"><i>b</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> from <span class=\"tex-span\"><i>b</i></span>. And we ask what is the minimum number of steps you need.</p><h4>Analysis:</h4><p>I bet there is a few people know the greedy method even if he/she have solved the early version before.</p><p><a href=\"//codeforces.com/problemset/problem/251/C\">Codeforces #153 Div 1. Problem C. Number Transformation</a></p><p>Let dp[k] denotes the minimum number of steps to transform b+k to b. In each step, you could only choose i which makes b+k-(b+k) mod x[i] minimal to calc dp[k]. It works bacause dp[0..k-1] is a monotone increasing function. Proof: - Say dp[k]=dp[k-t]+1.If t==1, then dp[0..k] is monotone increasing obviously.Otherwise dp[k-1]<=dp[k-t]+1=dp[k] (there must exist a x[i] makes b+k-1 also transform to b+k-t,and it is not necessarily the optimal decision of dp[k-1]). So dp[k] is a monotone increasing function, we can greedily calc dp[a-b].</p><p>In the first glance, it looks like something which will run in square complexity. But actually is linear. That is because, we could cut exactly max{<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>} in each 2 step. It can be proof by induction.</p><p>So the remians work is to delete those same <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>, and watch out some situation could cause degeneration. Many of us failed in this last step and got <strong>TLE</strong></p><h3><a href=\"//codeforces.com/problemset/problem/346/D\">Problem D. Robot Control</a></h3><p>Let's dp from t to s.</p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>Here dp[u] means, the minimum number of orders mzry1992 needs to send in the worst case. The left-hand-side is sending order while the right-hand side is not. At the beginning, we have dp[t] = 1, and dp[s] will be the answer.</p><p>We can see there is circular dependence in this equation, in this situation, one standard method is using Bellman-Ford algorithm to evaluate the dp function.</p><p>But it is not appropriate for this problem.</p><p>(In fact, we add a part of targeted datas in pretest, these datas are enough to block most of our <a href=\"https://en.wikipedia.org/wiki/Bellman%E2%80%93Ford_algorithm\">Bellman-Ford algorithm</a>, although there is still a few participator can get accepted by Bellman-Ford algorithm during the contest.</p><p>Check <a class=\"rated-user user-violet\" href=\"/profile/rares.buhai\" title=\"Candidate Master rares.buhai\">rares.buhai</a>'s <a href=\"//codeforces.com/contest/346/submission/4520171\">solution</a></p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>The expected solution is evaluating the dp function as the increased value of dp[u] itself. Further analysis shows, wheather we decided sending order or not in u can be judged as the out-degree of u.</p> <pre><code><br />while (!Q.empty()) {\n u = Q.front(), Q.pop_front()\n for each edge from v to u\n --out_degree[v]\n\tif (out_degree[v] == 0) {\n relax dp[v] by dp[u]\n if success, add v to the front of Q\n\t}\n\telse{\n\t relax dp[v] by dp[u] + 1\n\t if success, add v to the back of Q\n }\t\n }\n</code></pre><p>Check <a class=\"rated-user user-orange\" href=\"/profile/Ra16bit\" title=\"International Master Ra16bit\">Ra16bit</a>'s <a href=\"//codeforces.com/contest/346/submission/4519668\">solution</a> to see how it works.</p><h3><a href=\"//codeforces.com/problemset/problem/346/E\">Problem E. Doodle Jump</a></h3><h4>Brief description:</h4><p>You have been give <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>, <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>h</i></span> (gcd(<span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>) = 1), For each <span class=\"tex-span\"><i>ai</i></span> mod <span class=\"tex-span\"><i>p</i></span>, (<span class=\"tex-span\"><i>i</i></span>∈[1, n]), check weather the maximum distance in neighborhood after sorting is <= <span class=\"tex-span\"><i>h</i></span>. </p><h4>Analysis:</h4><p>Take <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 for example ... Divided the numbers in group.</p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 18\n</code></pre><p>We start a new group when the number > P</p><p>We found the difference between the elements of the first group is 5, The subsequent is filling some gap between the them ...</p><p>After some observation we could found that we should only consider into one gap ...(e.g. [0, 5] or [15, 20] or [20, 25] ... ) </p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>That says .. <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 is roughly equal to some things in small scale?</p><p>So let's check it in detail. Lemma 1. In any case, the gap after 20 won't better than any gap before it.</p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>For example, in this case, the gap after 20 is: 20, 22 And it has 16 in [15, 17] but no 21. </p><p>Is there any chance that [20, 23] is better than [15, 20]?</p><p>No, that is because, when there is no 21, then (19+5)%23 = 1, go to next floor. and there is no corresponding gap after 20 ([22, 24]) for this gap ([17, 19])</p><p>So we only need to consider [15, 20] ... and we found [15, 20] is roughly equal to [0, 5]</p> <pre><code>e.g. : 15 20 17 19 16 18 \nequal: 0 5 2 4 1 3\n</code></pre><p>we say 'roughly' because we havn't check some boundary case like there is 3 but on 18 ... </p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 \n</code></pre><p>If it happend, we should remove the number 3. .. If we can remove the element 5, then we can from a=5, p=23 to a'=2, p'=5 ...(n' = an/p, a' = a-p%a, if there is 3 but no 18, n'=n'-1)</p><p>The rest things is to discuss wheather 5 is necessary or not.</p><p>Let's we have:</p> <pre><code>0 2 4\n1 3\n</code></pre><p>If the 2*n'<5, then there is only one floor, the answer is max(2, 5-2*n'). If there is more than one floor, we could conclude that 5 is useless.</p><p>Proof: Elemets in 1st floor is: </p> <pre><code>0 a 2a 3a ...\n</code></pre><p>Let's say the maximum elements in 1st floor is x, then the minimum element in the 2nd floor is b0 = x+a-p, because b0 — a = x-p, so the difference between b0 and a is equal to the difference between x and p. That is, we can consider [b0, a] rather than [x, p], when there is a element insert in [b0, a], there must be some element insert in [x, p] in the same position.</p><p>So we have have succeeded to transform our original problem into a small one. Of couse, this problem havn't been solved, we haven't consider the time complexity. Says a' = a — p%a, when p = a+1, then a' = a-1, but we have <span class=\"tex-span\"><i>a</i></span> equal to 10^9, it won't work.</p><p>But, let's we have A1, A2, ... An ... and we subtract <span class=\"tex-span\"><i>d</i></span> from all of them, the answer won't be changed. So we can use p%a substitute for a-p%a, this is equivalent to we subtract %p% from all of them ...</p><p>So we set a' = min(a-p%a, p%a), so a'<=a/2, therefore, the final time complexity is <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span>.</p><p>You can check <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> <a href=\"//codeforces.com/contest/346/submission/4523388\">'s solution</a> for detail.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/346\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/347\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-4906-8958\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"4906\",\n blogEntryId: \"8903\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+56</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/MinakoKojima\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/MinakoKojima\">\n MinakoKojima\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8903#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8903#comments\">\n 66\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8974\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (56)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146290\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mohammadrdeh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/47/avatar/91eee3f7a5ec41f6.jpg'/> </a>\n <div><a href=\"/profile/mohammadrdeh\" title=\"Specialist mohammadrdeh\" class=\"rated-user user-cyan\">mohammadrdeh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146290\" href=\"?#comment-146290\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146290\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"14\"\r\n data-commentUserId=\"47\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+14</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146290\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>there is a typo: "... the classical <strong>LCA</strong> problem ..." => <strong>LCS</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146290 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146290 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146290\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146291\" commentParentId=\"146290\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146291\" href=\"?#comment-146291\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146290\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146291\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146291\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you. Fixed. m(_ _)m</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146291 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146291 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146291\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146297\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 05:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146297\" href=\"?#comment-146297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Actually our standard solution to C is O(b-a+n). O(b-a+n),O(b-a+nlogn),O((b-a+n)logn) are all able to pass during the test.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146297\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146335\" commentParentId=\"146297\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mmaxio\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/486/avatar/4bb53c24fc9e4c1.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/mmaxio\" title=\"International Master mmaxio\" class=\"rated-user user-orange\">mmaxio</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 17:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146335\" href=\"?#comment-146335\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146297\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146335\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146335\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"486\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146335\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>oh, never mind</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146335 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146335 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146335\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146299\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shashwat.gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6204/avatar/67f8e17c53f70578.jpg'/> </a>\n <div><a href=\"/profile/shashwat.gupta\" title=\"Specialist shashwat.gupta\" class=\"rated-user user-cyan\">shashwat.gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146299\" href=\"?#comment-146299\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146299\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"6204\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146299\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Problem B: Can you Explain little bit more on How "Aho-Corasick automation, or KMP" can help in figuring out smallest string that does not contain virus.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146299 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146299 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146299\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146300\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146300\" href=\"?#comment-146300\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146300\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146300\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For B, I already had the intuitive idea that this problem will be solved by either Aho-Corasick algorithm or KMP with dp, but I could not formalize the idea of states transition in dp. Could you please just provide the state in your dp algorithm?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146300 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146300 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146300\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146354\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146354\" href=\"?#comment-146354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146354\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Original problem can be solved by dp with two parameters DP[Len(s)] [Len(t)]. <a href=\"https://en.wikipedia.org/wiki/Longest_common_subsequence_problem\">http://en.wikipedia.org/wiki/Longest_common_subsequence_problem</a></p><p>To solve B you need to modificate it to DP[Len(s)][Len(t)][Len(virus)-1] where third parameter means maximum length of suffix of LCS that equal to prefix of virus.</p><p>To easy check where we go from K state (third parameter) by character C we can make automat on prefix function by virus.</p><p>Then if we stand in DP[i][j][k] :<br /> 1) if(s[i] == t[j] and Automat[k][c]<Len(virus) we try to relax DP[i+1][j+1][Automat[k][c]]<br /> 2) Try to relax DP[i][j+1][k] and DP[i+1][j][k]</p><p><strong>UPD</strong> My solution: <a href=\"//codeforces.com/contest/346/submission/4532899\">http://codeforces.com/contest/346/submission/4532899</a> (hope it understandable)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146354\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146357\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146357\" href=\"?#comment-146357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>got it, many thanks to you man :) Also understood why KMP tag mentioned in the problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146357\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146493\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lama\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/72190/avatar/735906a91d1576e3.jpg'/> </a>\n <div><a href=\"/profile/lama\" title=\"Expert lama\" class=\"rated-user user-blue\">lama</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 18:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146493\" href=\"?#comment-146493\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146493\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146493\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) Can you please explain what "maximum length of suffix of LCS that equal to prefix of virus" means? 2) What is an automat?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146493 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146493 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146493\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146519\" commentParentId=\"146493\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/25/2013 05:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146519\" href=\"?#comment-146519\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146493\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146519\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146519\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146519\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) We stand in DP[i][j][k]-state (in which we store longest LCS), virus = "virus" <br /> Let's go from k = 0 to 4,then:</p> <pre><code>0) DP[i][j][0] means that finded LCS not ends on "v" or "vi" or "vir" or "viru" or "virus". (example: "a")\n\n1) DP[i][j][1] means that finded LCS ends on "v", but not on "vi" or "vir" or "viru" or "virus". (example: "av")\n\n2) DP[i][j][2] means that finded LCS ends on "vi", but not on "vir" or "viru" or "virus". (example: "avi")\t\n\n3) DP[i][j][3] means that finded LCS ends on "vir", but not on "viru" or "virus". (example: "avir")\n\n4) DP[i][j][4] means that finded LCS ends on "viru", but not on "virus". (example: "aviru")\n\nWe take "longest suffix of LCS that equal prefix of virus", because virus could be: "vvvvv" or "ababv" (and infinite others)\n If LCS = "avvv" - it ends on "v","vv","vvv". (virus = "vvvvv")\n If LCS = "aabab" - it ends on "ab" and "abab". (virus = "ababv")\n</code></pre><p><a href=\"https://en.wikipedia.org/wiki/Knuth%E2%80%93Morris%E2%80%93Pratt_algorithm\">KMP</a></p><p>2) <a href=\"https://en.wikipedia.org/wiki/Automata_theory\">http://en.wikipedia.org/wiki/Automata_theory</a></p><p>Can't find nothing about automaton on prefix-function in english. I hope you will be able understand <a href=\"http://e-maxx.ru/algo/prefix_function\">this</a> with some translator (google translate for example).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146519 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146519 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146519\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"551712\" commentParentId=\"146519\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/srv_twry\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/447741/avatar/d1a80b00eb029c2b.jpg'/> </a>\n <div><a href=\"/profile/srv_twry\" title=\"Expert srv_twry\" class=\"rated-user user-blue\">srv_twry</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/19/2019 12:58\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-551712\" href=\"?#comment-551712\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146519\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"551712\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"447741\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-551712\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Fortunately, the e-maxx article on Prefix function has been translated in English and can be found here: <a href=\"https://cp-algorithms.com/string/prefix-function.html#toc-tgt-12\">prefix-function: automaton on prefix-function</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-551712 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-551712 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-551712\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"768401\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ttbbnnn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1694563/avatar/ff85df0301cf6f76.jpg'/> </a>\n <div><a href=\"/profile/ttbbnnn\" title=\"Master ttbbnnn\" class=\"rated-user user-orange\">ttbbnnn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2021 20:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-768401\" href=\"?#comment-768401\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"768401\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1694563\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-768401\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My solution for B got a WA on test 41 and I don't know why :<, please help me with this code: <a href=\"https://codeforces.com/contest/346/submission/109283664\">https://codeforces.com/contest/346/submission/109283664</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-768401 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-768401 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-768401\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146301\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146301\" href=\"?#comment-146301\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146301\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146301\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146301\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"So the remians work is to delete those same xi, and watch out some situation could cause degeneration. Many of us failed in this last step and got TLE", I really could not understand this. What you you mean by degeneration in this case? Please explain this last important step.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146301 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146301 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146301\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146302\" commentParentId=\"146301\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:37\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146302\" href=\"?#comment-146302\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146301\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146302\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146302\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>suppose b=1, all x[i]>a, what will happen?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146302 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146302 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146302\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146304\" commentParentId=\"146302\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146304\" href=\"?#comment-146304\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146302\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146304\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146304\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As b = 1, All x[i] > a. Then a % x[i] = a. So if we take this, then we will lead to a — a = 0, which is less than b. So we need to move one by one, so answer would be a.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146304 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146304 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146304\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146309\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146309\" href=\"?#comment-146309\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146309\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146309\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Alice and Bob problem how do you prove that you will always get {d, 2d, 3d, ... max{xi}} in the end. It is easy to see but I am unable to prove it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146309 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146309 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146309\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146365\" commentParentId=\"146309\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marat.snowbear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98082/avatar/1499cf6d0c86172.jpg'/> </a>\n <div><a href=\"/profile/marat.snowbear\" title=\"International Master marat.snowbear\" class=\"rated-user user-orange\">marat.snowbear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146365\" href=\"?#comment-146365\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146309\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146365\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"98082\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146365\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I convinced myself like this:</p> <ol> <li>Prove that we will be able to get d by some sequence of subtractions.</li> <li>Prove that we will be able to generate {d, 2d, 3d, ...}</li> <li>Prove that we will not be able to get anything else except for { d, 2d, 3d, ... }</li> </ol><p>In details:</p> <ol> <li><p>See <a href=\"https://en.wikipedia.org/wiki/Euclidean_algorithm\">Euclidean algorithm for finding GCD</a>. If you will look into the description or code you will see that it does exactly what is asked in this problem — subtracts numbers one from another. And the result is GCD of original two numbers. So you can see that by some sequence of subtractions you can get GCD.</p></li> <li><p>If you already have d which GCD of all the numbers then you can easily fill all the gaps in { d, 2d, 3d, ..., max } sequence by starting subtracting d from { max, max — d, max — 2d, ... }. So you will get the intended set.</p></li> <li><p>You cannot subtract two numbers a and b which have GCD(a, b) = d and get result which won't be dividable by d. So if you start with set where every numbers can be divided by d then no matter what you subtract you will always have the result which is also dividable by d.</p></li> </ol></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146365 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146365 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146365\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146390\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 16:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146390\" href=\"?#comment-146390\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146390\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146390\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, got it. Thanks!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146390 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146390 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146390\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"774539\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/25/2021 20:24\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-774539\" href=\"?#comment-774539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"774539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-774539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-774539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-774539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-774539\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146310\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i_coder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i_coder\" title=\"Expert i_coder\" class=\"rated-user user-blue\">i_coder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146310\" href=\"?#comment-146310\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146310\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"41979\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146310\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Is this the final editorial (except the D problem) ? The explanations to problems B and C are very limited and not at all well elaborated.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146310 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146310 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146310\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146314\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146314\" href=\"?#comment-146314\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146314\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146314\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can you tell me that why the number of rounds in Problem A will be max(xi)/d-n ? How do you come to this point ? can you please tell me this as am not to figure out this thing ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146314 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146314 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146314\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146316\" commentParentId=\"146314\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:45\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146316\" href=\"?#comment-146316\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146314\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146316\" revisionCount=\"7\" revision=\"7\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">7</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146316\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146316\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>take example <br /> 3 9 54 <br /> gcd (3, 9, 54) = 3 <br /> Now total rounds possible including (3, 9, 54) =<br />all multiples of 3 upto 54 <br /> 3, 6, 9, 12, 15, 18 ... 54 <br /> </p><p>So total count of these numbers = 54 / 3 = 18. <br /> </p><p>Now as out of these numbers 3 numbers are already taken, so subtract 3 <br /> so rounds remaining = 18 — 3 = 15 </p><p>Now it is very easy to generalize for 3 being d and 54 being n</p><p>answer would be n / d — n. <br /> I hope it is clear now :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146316 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146316 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146316\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146319\" commentParentId=\"146316\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146319\" href=\"?#comment-146319\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146316\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146319\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146319\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes, it is more clear to me now. but one thing is that how did you approach to gcd thing ? I understood the problem, the logic and all. how did you approach that it will be done using gcd thing and all ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146319 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146319 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146319\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146322\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146322\" href=\"?#comment-146322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146322\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My Ideas during solving the problem: <br /> all the examples had gcd 1. So I directly thought answer as max(xi) — n. <br /> But I thought it can not be too simple, I need to think more. <br /> So I took a case 2 4 6, I immediately found I am wrong in this case. <br /> Then the idea came into mind that if gcd of numbers is g. then we can not create any number not divisible by g because (g *k1 — k * k2) = g * (k1 — k2). </p><p>So Finally I coded it and got accpeted :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146322\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146338\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 19:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146338\" href=\"?#comment-146338\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146338\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146338\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>given the numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>, what is the minimum positive value you can achieve by combining them? </p><p>Let's write down the equation: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>·<i>x</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub>·<i>x</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>n</i></sub>·<i>x</i><sub class=\"lower-index\"><i>n</i></sub> = <i>d</i></span>, where <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> are some unknown integers. </p><p>It is, as you can see, none other than linear Diophantine equation. And it is known there is no solutions if <span class=\"tex-span\"><i>d</i></span> is not a multiple of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span> </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146338 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146338 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146338\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146317\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/subway\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123924/avatar/706e86f587cbabf0.jpg'/> </a>\n <div><a href=\"/profile/subway\" title=\"Expert subway\" class=\"rated-user user-blue\">subway</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146317\" href=\"?#comment-146317\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146317\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146317\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@hellodear-the final set will contain all elements {d,2d,3d,..max(Xi)} (d=gcd of all elements) so total no. of elements in final set =max(Xi)/d since initially we have 'n' elements total no. of new elements to be added in set to make it complete=(max(Xi)/d)-n.. hope this helps you..:)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146317 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146317 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146317\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146320\" commentParentId=\"146317\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146320\" href=\"?#comment-146320\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146317\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146320\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146320\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in this thing, I was applying some game theory, but it doesn't include anything like that. when the question says optimally, then how do you form examples so as to test your code on them ? because optimally means in the best they can. can you elaborate ? thanks to you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146320 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146320 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146320\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146324\" commentParentId=\"146320\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146324\" href=\"?#comment-146324\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146320\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146324\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146324\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146324\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>optimality argument is simple and also given in the editorial itself. <br /> As total you numbers finally would be {d, 2 * d,, .,, max (xi)}. <br /> Hence whatever you add to the these set, no other person will be able to add that as he has to add a new number everytime to this test. <br /> So outcome depend on the parity of turns.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146324 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146324 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146324\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146325\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sinamosavi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/87557/avatar/bde58fa97bcc5eb0.jpg'/> </a>\n <div><a href=\"/profile/sinamosavi\" title=\"Pupil sinamosavi\" class=\"rated-user user-green\">sinamosavi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146325\" href=\"?#comment-146325\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146325\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"87557\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146325\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the complete proof for A.Div1 is not that much straightforward. Maybe I'm making it too much difficult, but this is my complete proof:</p><p>First by induction, we prove that the numbers in the end will be <span class=\"tex-span\"><i>a</i>, 2<i>a</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Let <span class=\"tex-span\"><i>g</i> = <i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ... , <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span>. It's trivial that in the end <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>. Assume that <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>, because our numbers will be <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), 2<i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>, so we would have a new gcd. That's a contradiction, so <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) = <i>g</i></span> and our numbers will be <span class=\"tex-span\"><i>g</i>, 2<i>g</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Each move adds one number and in the end there will be <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e6ac12549498d8aaad3d63270d12497bc74a9f84.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> numbers, so the answer wil be the parity of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/48ba1bfd0fa315ab1595947b8e046b4cc211b908.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Sorry for my bad English.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146325 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146325 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146325\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146332\" commentParentId=\"146325\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146332\" href=\"?#comment-146332\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146325\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146332\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-13\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146332\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What about this test <code>2 3 5</code>? <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≠ <i>gcd</i></span></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146332 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146332 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146332\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146333\" commentParentId=\"146332\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146333\" href=\"?#comment-146333\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146332\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146333\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146333\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Oops. You've meant that <span class=\"tex-span\"><i>a</i></span> — is the result. Sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146333 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146333 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146333\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146334\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 16:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146334\" href=\"?#comment-146334\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146334\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146334\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146334\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>But how to prove that there is always a way to choose <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> while the number of the current round less than the maximum number of rounds? (Div2C)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146334 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146334 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146334\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146339\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:22\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146339\" href=\"?#comment-146339\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146339\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146339\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146339\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If gcd{xi}＝1, then for every xi there must exist ti to make sum｛xi*ti｝＝1. </p><p>(For example, x1＝5,x2＝7,then t1＝3,t2＝-2.x1*t1＋x2*t2＝1.)</p><p>And sum{xi*ti} can be performed in a few turns. ( (5-(7-5))-(7-5). )</p><p>And if we can get 1, then what number between [1,max{xi}] can't we get？</p><p>if gcd{xi}≠1.the proof is similar.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146339 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146339 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146339\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146341\" commentParentId=\"146339\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146341\" href=\"?#comment-146341\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146339\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146341\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146341\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why there is must exist such t[i]?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146341 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146341 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146341\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146366\" commentParentId=\"146341\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146366\" href=\"?#comment-146366\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146341\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146366\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146366\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You must know if gcd(a,b)＝1, there must exist x and y to make ax＋by＝1. It can be proved from this.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146366 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146366 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146366\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146376\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146376\" href=\"?#comment-146376\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146376\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146376\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146376\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So.. If we divide all the numbers by GCD, and after that a pair of coprime numbers have appeared, we always can reach 1. Let's choose coprime <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, then <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> will be also coprime with <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, and it will be less then <span class=\"tex-span\"><i>max</i>(<i>x</i>, <i>y</i>)</span>. So we can choose <span class=\"tex-span\"><i>mid</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>x</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>min</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>y</i><sub class=\"lower-index\">1</sub></span>, and they are coprime, and <span class=\"tex-span\">|<i>x</i><sub class=\"lower-index\">1</sub> - <i>y</i><sub class=\"lower-index\">1</sub>|</span> will be less than <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>. And etc. by induction. But what to do if there is not a pair of coprime numbers after dividing by GCD? For example <code>35 45 63</code>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146376 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146376 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146376\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146404\" commentParentId=\"146376\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146404\" href=\"?#comment-146404\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146376\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146404\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146404\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146404\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>63*2＋45*5＋35*(-10)＝1</p><p>Because gcd (35,45)＝5, we can consider 35 and 45 as one number 5x. Because gcd(5,63)＝1, so there must exist x,y to make 5x＋63y＝1.</p><p>So here comes a tragedy. We can get 5 first. Then we use this number together with 63 to make 1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146404 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146404 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146404\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146346\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KiAsaGibona\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/KiAsaGibona\" title=\"Specialist KiAsaGibona\" class=\"rated-user user-cyan\">KiAsaGibona</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 21:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146346\" href=\"?#comment-146346\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146346\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146346\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"99053\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146346\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Someone please explain the greedy idea of (Div 1 C) (Number Transformation II). Thanks in advance :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146346 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146346 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146346\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146367\" commentParentId=\"146346\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 09:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146367\" href=\"?#comment-146367\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146346\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146367\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146367\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's a pretty simple greedy idea: Just pick the <code>x</code> that makes the value of <code>a</code> smallest after applying the operation <code>a = a - a%x</code> (or subtract 1 if no choice for <code>x</code> makes <code>a</code> smaller). The proof why this works is given in the editorial: it is never better to get a larger number, so you should get the smallest one you can.</p><p>As listed on the last paragraph of the editorial you have to be careful to remove all <code>x</code> that are either duplicates or cannot be used anymore (<code>a - (a%x)</code> is smaller than <code>b</code>), otherwise you will get TLE.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146367 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146367 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146367\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146382\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146382\" href=\"?#comment-146382\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146382\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146382\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146382\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>how to find this x for each number?</p><p>we will iterate on all x[i]s and only delete x[i]s when x[i] > a?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146382 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146382 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146382\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146405\" commentParentId=\"146382\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146405\" href=\"?#comment-146405\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146382\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146405\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146405\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Iterate through all x[i]s and delete them when a — (a%x[i]) is smaller than b (if you only delete when x[i] > a, you will also get TLE).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146405 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146405 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146405\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146625\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 17:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146625\" href=\"?#comment-146625\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146625\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146625\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm really striving to understand why the algorithm turns out to be linear instead of quadratic... I know the editorial says "That is because, we could cut exactly <span class=\"tex-span\"><i>max</i>{<i>xi</i>}</span> in each 2 step.", but I can't really get what it means :\\</p><p>Can you give me a hint? Thanks :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146625 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146625 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146625\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146643\" commentParentId=\"146625\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/xenoslash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88090/avatar/f75f8cbc20d6133f.jpg'/> </a>\n <div><a href=\"/profile/xenoslash\" title=\"Expert xenoslash\" class=\"rated-user user-blue\">xenoslash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 19:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146643\" href=\"?#comment-146643\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146625\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146643\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146643\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"88090\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146643\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have an easy intuition of cutting at least max{xi} in O(1) steps, not sure what was the intended 2 step proofs though. I am going to use xi to refer to max{xi}, and assume that proper care is taken to only keep the relevant xi's.</p><p>When we do a-(a % xi), we bring caused a to be the next largest integer <= a that is a multiple of xi, since now new_a % xi = 0. Then, if a is divisible by xi, you can do.., do a-1 (causing it to be non-divisible by xi), then finally a-(a%xi) again. In this 3 step sequence you have brought a down to the next lower multiple of xi, and have essentially cut max{xi} in O(1) number of steps.</p><p>Sample code : <a href=\"//codeforces.com/contest/346/submission/4545367\">http://codeforces.com/contest/346/submission/4545367</a> Yeah I used tree set so it's not exactly O(n).. but hash set keeps giving me TLE :(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146643 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146643 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146643\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146689\" commentParentId=\"146643\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2013 12:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146689\" href=\"?#comment-146689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146643\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you very much, that was really eye-opening! This is why I love Codeforces, great community! :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146689\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146371\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Corvo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/11909/avatar/8404ac1aff5270ec.jpg'/> </a>\n <div><a href=\"/profile/Corvo\" title=\"Pupil Corvo\" class=\"rated-user user-green\">Corvo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 12:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146371\" href=\"?#comment-146371\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146371\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"11909\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146371\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please explain why the problem is solved through the GDC (A)? I tried like <a href=\"https://codeforces.com/contest/347/submission/4535232\">this</a>, but I still can not understand why you can not do. Please give a short test on which the decision falls. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146371 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146371 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146371\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146375\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146375\" href=\"?#comment-146375\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146375\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146375\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><pre><code>3\n14 4 2\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146375 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146375 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146375\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146378\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akashdeep\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/39866/avatar/6f66d1bbe26ef4ca.jpg'/> </a>\n <div><a href=\"/profile/akashdeep\" title=\"International Master akashdeep\" class=\"rated-user user-orange\">akashdeep</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146378\" href=\"?#comment-146378\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146378\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"39866\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146378\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Because only those numbers are possible in the game which are multiple of gcd. See this simplest test case</p> <pre><code>2\n4 6\n</code></pre><p>The only number possible in the game is (6-4) i.e. 2, but in your code u are assuming that somehow these (1,2,3,5) numbers can be obtained which is a wrong assumption.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146378 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146378 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146378\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146408\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/NegaTeeF\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/NegaTeeF\" title=\"Master NegaTeeF\" class=\"rated-user user-orange\">NegaTeeF</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 20:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146408\" href=\"?#comment-146408\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146408\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"65829\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146408\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Explain please, how to do Div1-D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146408 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146408 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146408\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146410\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/irakli_p\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29034/avatar/d879a3156498c6c7.jpg'/> </a>\n <div><a href=\"/profile/irakli_p\" title=\"Expert irakli_p\" class=\"rated-user user-blue\">irakli_p</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 21:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146410\" href=\"?#comment-146410\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146410\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29034\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146410\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i didn't understand Div 2 — D can someone explain it to me please </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146410 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146410 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146410\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146443\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/suiyuan2009\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49923/avatar/9065a92c0b30b883.jpg'/> </a>\n <div><a href=\"/profile/suiyuan2009\" title=\"Master suiyuan2009\" class=\"rated-user user-orange\">suiyuan2009</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 13:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146443\" href=\"?#comment-146443\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146443\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49923\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146443\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>problem B,ac automachine is doing the thing that belong to kmp</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146443 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146443 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146443\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146452\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 17:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146452\" href=\"?#comment-146452\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146452\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146452\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div1_E: Should the "Doodler" jump over the platform which H = P ? I just confused about that.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146452 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146452 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146452\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146480\" commentParentId=\"146452\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 11:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146480\" href=\"?#comment-146480\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146452\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146480\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146480\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OK I got the answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146480 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146480 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146480\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146463\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146463\" href=\"?#comment-146463\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146463\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"44\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+44</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146463\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>still waiting for D tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146463 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146463 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146463\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147566\" commentParentId=\"146463\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/05/2013 05:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147566\" href=\"?#comment-147566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146463\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>.. Update .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147566\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"235917\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/saurabhverma\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/143428/avatar/48808a8d5db775d4.jpg'/> </a>\n <div><a href=\"/profile/saurabhverma\" title=\"Expert saurabhverma\" class=\"rated-user user-blue\">saurabhverma</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2015 20:05\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-235917\" href=\"?#comment-235917\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"235917\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"143428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-235917\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In my approach to problem div1 B, I calculated longest common subsequence, prepended virus to it, calculated the Z function and deleted every character which had z[i] >= virus.size(). I don't think my approach is wrong. Can someone tell me if my code is wrong or the approach has some flaw. Thanks. Submission : <a href=\"//codeforces.com/contest/346/submission/11491420\">http://codeforces.com/contest/346/submission/11491420</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-235917 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-235917 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-235917\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"530287\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arpit4427\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/717924/avatar/90dcbc94a1e57cf.jpg'/> </a>\n <div><a href=\"/profile/arpit4427\" title=\"Expert arpit4427\" class=\"rated-user user-blue\">arpit4427</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/26/2019 14:04\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-530287\" href=\"?#comment-530287\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"530287\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"530287\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"717924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-530287\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone explain how to solve this problem <a href=\"/contest/346/problem/B\" title=\"Codeforces Round 201 (Div. 1)\">346B - Lucky Common Subsequence</a>? I have went thorugh the editorial but I could not understand.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-530287 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-530287 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-530287\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8974\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8974 = true;\r\nvar lastPreviewContent8974 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8974] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8974] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:24</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812874998e81759f',t:'MTY5NjcwNTk0NS4wMjkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1756,"cells":{"problem_id":{"kind":"string","value":"347E"},"contest":{"kind":"string","value":"347"},"problem":{"kind":"string","value":"E"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"E. Number Transformation II"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Number Transformation II</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are given a sequence of positive integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> and two non-negative integers <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span>. Your task is to transform <span class=\"tex-span\"><i>a</i></span> into <span class=\"tex-span\"><i>b</i></span>. To do that, you can perform the following moves:</p><ul> <li> subtract 1 from the current <span class=\"tex-span\"><i>a</i></span>; </li><li> subtract <span class=\"tex-span\"><i>a</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ <i>n</i>)</span> from the current <span class=\"tex-span\"><i>a</i></span>. </li></ul><p>Operation <span class=\"tex-span\"><i>a</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> means taking the remainder after division of number <span class=\"tex-span\"><i>a</i></span> by number <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>Now you want to know the minimum number of moves needed to transform <span class=\"tex-span\"><i>a</i></span> into <span class=\"tex-span\"><i>b</i></span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a single integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup></span>). The second line contains <span class=\"tex-span\"><i>n</i></span> space-separated integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">2 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>). The third line contains two integers <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span> (<span class=\"tex-span\">0 ≤ <i>b</i> ≤ <i>a</i> ≤ 10<sup class=\"upper-index\">9</sup></span>, <span class=\"tex-span\"><i>a</i> - <i>b</i> ≤ 10<sup class=\"upper-index\">6</sup></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the required minimum number of moves needed to transform number <span class=\"tex-span\"><i>a</i></span> into number <span class=\"tex-span\"><i>b</i></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>3 4 5<br/>30 17<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>5 6 7<br/>1000 200<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>206<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"12e807ce6ff9c5fee7469b00cb3371e5\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"f8f8f6cf474a1d90f03554b971b57bc6697e07dd\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='12e807ce6ff9c5fee7469b00cb3371e5'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F347%2Fproblem%2FE%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='12e807ce6ff9c5fee7469b00cb3371e5'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/347\">Codeforces Round 201 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='12e807ce6ff9c5fee7469b00cb3371e5'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/347/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Number theory: Euler function, GCD, divisibility, etc\">\r\n number theory\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2200\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='12e807ce6ff9c5fee7469b00cb3371e5'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3512\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='12e807ce6ff9c5fee7469b00cb3371e5'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3512\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8896\" title=\"Codeforces Round #201\" target=\"_blank\">Codeforces Round #201</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1862:1863\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8903\" title=\"Codeforces Round #201 Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1865\" resourceName=\"Codeforces Round #201 Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/347\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/347/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/347/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/347/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/347/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/347/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/347/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/347/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_f84e17642123c1d3c31bb119f1562a42f7df5f2b\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Number Transformation II</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are given a sequence of positive integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> and two non-negative integers <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span>. Your task is to transform <span class=\"tex-span\"><i>a</i></span> into <span class=\"tex-span\"><i>b</i></span>. To do that, you can perform the following moves:</p><ul> <li> subtract 1 from the current <span class=\"tex-span\"><i>a</i></span>; </li><li> subtract <span class=\"tex-span\"><i>a</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ <i>n</i>)</span> from the current <span class=\"tex-span\"><i>a</i></span>. </li></ul><p>Operation <span class=\"tex-span\"><i>a</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> means taking the remainder after division of number <span class=\"tex-span\"><i>a</i></span> by number <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>Now you want to know the minimum number of moves needed to transform <span class=\"tex-span\"><i>a</i></span> into <span class=\"tex-span\"><i>b</i></span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a single integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup></span>). The second line contains <span class=\"tex-span\"><i>n</i></span> space-separated integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">2 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>). The third line contains two integers <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span> (<span class=\"tex-span\">0 ≤ <i>b</i> ≤ <i>a</i> ≤ 10<sup class=\"upper-index\">9</sup></span>, <span class=\"tex-span\"><i>a</i> - <i>b</i> ≤ 10<sup class=\"upper-index\">6</sup></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the required minimum number of moves needed to transform number <span class=\"tex-span\"><i>a</i></span> into number <span class=\"tex-span\"><i>b</i></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />3 4 5<br />30 17<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />5 6 7<br />1000 200<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>206<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:33:58</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122be0d6b8c0022',t:'MTY5NjY0NjAzOC42ODIwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Dynamic programming\", \"Greedy algorithms\", \"Number theory: Euler function, GCD, divisibility, etc\"]"},"short_tags":{"kind":"string","value":"[\"dp\", \"greedy\", \"number theory\", \"*2200\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/8903"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"1c88316eb9ff5851524d80ea59ef3f32\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #201 Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #201 Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='1c88316eb9ff5851524d80ea59ef3f32'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F8903\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:36</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='1c88316eb9ff5851524d80ea59ef3f32'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/MinakoKojima\">MinakoKojima</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/MinakoKojima\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/MinakoKojima\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/MinakoKojima\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/MinakoKojima\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/MinakoKojima\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/MinakoKojima\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/MinakoKojima\" style=\"text-decoration:none;color:black !important;\">MinakoKojima's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"8958\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/8903\"> <p>Codeforces Round #201 Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a>,\r\n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><img alt=\" \" src=\"/predownloaded/41/3f/413f7303374a112dddc1e63e29cfc12924514cd7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><h1>Overview</h1><p>In DIV 1, there are 4 interesting problems together with a normal one. We think it is reasonable because we can't have a round fullly with intelligence. Problem A, C have weak pretests while others intended to be strong. About more then 200 participants solve A in the early 45mins, then a few of them start from C while most of the other start from B. </p><p>Problem B is a rather standard problem, but if you're unfamiliar with the algorithm, it can be very hard. Problem C is a more intersting problem. As the name implies, there was <a href=\"//codeforces.com/problemset/problem/251/C\">a similar version</a> in the previous round before, but this time it has a brand new constrains.(So here we have a psychology experiment: could different constrains make people thinking in a slightly different way?ww)</p><p>The standard solution of problem C is <span class=\"tex-span\"><i>O</i>((<i>b</i> - <i>a</i>) + <i>nlogn</i>)</span>. The first expected correct solution was written by <a class=\"rated-user user-orange\" href=\"/profile/zeliboba\" title=\"International Master zeliboba\">zeliboba</a>. <a href=\"//codeforces.com/contest/346/submission/4512654\">http://codeforces.com/contest/346/submission/4512654</a></p><p>After that, some people start to solve problem D. Problem D looks like a hard dp problem on a graph at the first glance, the key point is how to avoid the circle in the transfer equation. It turn out to be elegant after you could found a right order of the evaluation. Problem E is challenging which you need find a way to transform the original question into a smaller scale, and cut off many many corner cases ... And in the very end, you find a way like binary search to get <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span> as the time complexity. No one manage to solve problem E during the contest, maybe <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> is the man who closest to it.</p><p>The winner comes to <a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"Grandmaster cgy4ever\">cgy4ever</a>, because he found the draw-black in his previous C submission during the very beginning even when there is nobody hack him! He resubmit it decisively and get back when finished problem D. After that, he use the same trick which made him failed before to hack others and got a handsomely rewards. The second place went to <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a>, because of the combination of decent speed in A, B, C, D.</p><p>Problem B belongs to me, problem C belongs to <a class=\"rated-user user-violet\" href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\">CMHJT</a> and others belong to <a class=\"rated-user user-orange\" href=\"/profile/UESTC_Nocturne\" title=\"International Master UESTC_Nocturne\">UESTC_Nocturne</a>. The illustrator of problem C is <a href=\"http://www.pixiv.net/member_illust.php?mode=medium&illust_id=38602657\">Chairman Miao(貓主席)</a>.</p><h1>Editorial</h1><h3><a href=\"//codeforces.com/problemset/problem/346/A\">Problem A. Alice and Bob</a></h3><h4>Brief description:</h4><p>Alice and Bob play a game, the rules are as follows: First, they will get a set of <span class=\"tex-span\"><i>n</i></span> distinct numbers. And then they take turns to do the following operations. During each operation, either Alice or Bob can choose two different numbers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> from the set, as long as <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> is not in the set, then they add it to the set. The person who can not choose two numbers successfully will lose the game. The question is who will finally win the game if both of them do operations optimally. Remember that Alice always goes first.</p><h4>Analysis:</h4><p>First, no matter what happend, the number set we get at the very endding will be same all the time. Let's say <span class=\"tex-span\"><i>d</i> = <i>gcd</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}. Then the set in the endding will be some things like {<span class=\"tex-span\"><i>d</i></span>, <span class=\"tex-span\">2<i>d</i></span>, <span class=\"tex-span\">3<i>d</i></span>, ... <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>}}. So there is always <span class=\"tex-span\"><i>max</i>{<i>x</i><sub class=\"lower-index\"><i>i</i></sub>} / <i>d</i></span> — <span class=\"tex-span\"><i>n</i></span> rounds. And what we should do rest is to check the parity of this value.</p><h3><a href=\"//codeforces.com/problemset/problem/346/B\">Problem B. Lucky Common Subsequence</a></h3><h4>Brief description:</h4><p>You have been given two strings <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> and <span class=\"tex-span\"><i>virus</i></span>, and you have to find the longest common subsequence of <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\">2</sub></span> without <span class=\"tex-span\"><i>virus</i></span> as a substring.</p><h4>Analysis:</h4><p>This is a rather classical problem, let's say if there is no virus, then it is the classical **LCS ** problem. You can solve this by a <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> dynamic programing.</p><p>When consider about the virus, we should add 1 more dimension on the state to trace the growth of the virus. It can be done by wheather <strong>Aho-Corasick automation</strong>, or <strong>KMP</strong> when there is only one virus in this case. The overall time complexity is <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">3</sup>)</span>.</p><h3><a href=\"//codeforces.com/problemset/problem/346/C\">Problem C. Number Transformation II</a></h3><h4>Brief description:</h4><p>You have a number <span class=\"tex-span\"><i>b</i></span>, and want to minus it to <span class=\"tex-span\"><i>a</i></span>, what you can do in each step is weather subtract 1 or <span class=\"tex-span\"><i>b</i></span> mod <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> from <span class=\"tex-span\"><i>b</i></span>. And we ask what is the minimum number of steps you need.</p><h4>Analysis:</h4><p>I bet there is a few people know the greedy method even if he/she have solved the early version before.</p><p><a href=\"//codeforces.com/problemset/problem/251/C\">Codeforces #153 Div 1. Problem C. Number Transformation</a></p><p>Let dp[k] denotes the minimum number of steps to transform b+k to b. In each step, you could only choose i which makes b+k-(b+k) mod x[i] minimal to calc dp[k]. It works bacause dp[0..k-1] is a monotone increasing function. Proof: - Say dp[k]=dp[k-t]+1.If t==1, then dp[0..k] is monotone increasing obviously.Otherwise dp[k-1]<=dp[k-t]+1=dp[k] (there must exist a x[i] makes b+k-1 also transform to b+k-t,and it is not necessarily the optimal decision of dp[k-1]). So dp[k] is a monotone increasing function, we can greedily calc dp[a-b].</p><p>In the first glance, it looks like something which will run in square complexity. But actually is linear. That is because, we could cut exactly max{<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>} in each 2 step. It can be proof by induction.</p><p>So the remians work is to delete those same <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>, and watch out some situation could cause degeneration. Many of us failed in this last step and got <strong>TLE</strong></p><h3><a href=\"//codeforces.com/problemset/problem/346/D\">Problem D. Robot Control</a></h3><p>Let's dp from t to s.</p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>Here dp[u] means, the minimum number of orders mzry1992 needs to send in the worst case. The left-hand-side is sending order while the right-hand side is not. At the beginning, we have dp[t] = 1, and dp[s] will be the answer.</p><p>We can see there is circular dependence in this equation, in this situation, one standard method is using Bellman-Ford algorithm to evaluate the dp function.</p><p>But it is not appropriate for this problem.</p><p>(In fact, we add a part of targeted datas in pretest, these datas are enough to block most of our <a href=\"https://en.wikipedia.org/wiki/Bellman%E2%80%93Ford_algorithm\">Bellman-Ford algorithm</a>, although there is still a few participator can get accepted by Bellman-Ford algorithm during the contest.</p><p>Check <a class=\"rated-user user-violet\" href=\"/profile/rares.buhai\" title=\"Candidate Master rares.buhai\">rares.buhai</a>'s <a href=\"//codeforces.com/contest/346/submission/4520171\">solution</a></p><p>dp[u] = min(min(dp[v]) + 1 , max(dp[v])) | u->v</p><p>The expected solution is evaluating the dp function as the increased value of dp[u] itself. Further analysis shows, wheather we decided sending order or not in u can be judged as the out-degree of u.</p> <pre><code><br />while (!Q.empty()) {\n u = Q.front(), Q.pop_front()\n for each edge from v to u\n --out_degree[v]\n\tif (out_degree[v] == 0) {\n relax dp[v] by dp[u]\n if success, add v to the front of Q\n\t}\n\telse{\n\t relax dp[v] by dp[u] + 1\n\t if success, add v to the back of Q\n }\t\n }\n</code></pre><p>Check <a class=\"rated-user user-orange\" href=\"/profile/Ra16bit\" title=\"International Master Ra16bit\">Ra16bit</a>'s <a href=\"//codeforces.com/contest/346/submission/4519668\">solution</a> to see how it works.</p><h3><a href=\"//codeforces.com/problemset/problem/346/E\">Problem E. Doodle Jump</a></h3><h4>Brief description:</h4><p>You have been give <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>, <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>h</i></span> (gcd(<span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>p</i></span>) = 1), For each <span class=\"tex-span\"><i>ai</i></span> mod <span class=\"tex-span\"><i>p</i></span>, (<span class=\"tex-span\"><i>i</i></span>∈[1, n]), check weather the maximum distance in neighborhood after sorting is <= <span class=\"tex-span\"><i>h</i></span>. </p><h4>Analysis:</h4><p>Take <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 for example ... Divided the numbers in group.</p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 18\n</code></pre><p>We start a new group when the number > P</p><p>We found the difference between the elements of the first group is 5, The subsequent is filling some gap between the them ...</p><p>After some observation we could found that we should only consider into one gap ...(e.g. [0, 5] or [15, 20] or [20, 25] ... ) </p> <pre><code>0 5 10 15 20\n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>That says .. <span class=\"tex-span\"><i>a</i></span> =5, <span class=\"tex-span\"><i>p</i></span> =23 is roughly equal to some things in small scale?</p><p>So let's check it in detail. Lemma 1. In any case, the gap after 20 won't better than any gap before it.</p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16\n</code></pre><p>For example, in this case, the gap after 20 is: 20, 22 And it has 16 in [15, 17] but no 21. </p><p>Is there any chance that [20, 23] is better than [15, 20]?</p><p>No, that is because, when there is no 21, then (19+5)%23 = 1, go to next floor. and there is no corresponding gap after 20 ([22, 24]) for this gap ([17, 19])</p><p>So we only need to consider [15, 20] ... and we found [15, 20] is roughly equal to [0, 5]</p> <pre><code>e.g. : 15 20 17 19 16 18 \nequal: 0 5 2 4 1 3\n</code></pre><p>we say 'roughly' because we havn't check some boundary case like there is 3 but on 18 ... </p> <pre><code>0 5 10 15 20 \n2 7 12 17 22\n4 9 14 19\n1 6 11 16 21\n3 8 13 \n</code></pre><p>If it happend, we should remove the number 3. .. If we can remove the element 5, then we can from a=5, p=23 to a'=2, p'=5 ...(n' = an/p, a' = a-p%a, if there is 3 but no 18, n'=n'-1)</p><p>The rest things is to discuss wheather 5 is necessary or not.</p><p>Let's we have:</p> <pre><code>0 2 4\n1 3\n</code></pre><p>If the 2*n'<5, then there is only one floor, the answer is max(2, 5-2*n'). If there is more than one floor, we could conclude that 5 is useless.</p><p>Proof: Elemets in 1st floor is: </p> <pre><code>0 a 2a 3a ...\n</code></pre><p>Let's say the maximum elements in 1st floor is x, then the minimum element in the 2nd floor is b0 = x+a-p, because b0 — a = x-p, so the difference between b0 and a is equal to the difference between x and p. That is, we can consider [b0, a] rather than [x, p], when there is a element insert in [b0, a], there must be some element insert in [x, p] in the same position.</p><p>So we have have succeeded to transform our original problem into a small one. Of couse, this problem havn't been solved, we haven't consider the time complexity. Says a' = a — p%a, when p = a+1, then a' = a-1, but we have <span class=\"tex-span\"><i>a</i></span> equal to 10^9, it won't work.</p><p>But, let's we have A1, A2, ... An ... and we subtract <span class=\"tex-span\"><i>d</i></span> from all of them, the answer won't be changed. So we can use p%a substitute for a-p%a, this is equivalent to we subtract %p% from all of them ...</p><p>So we set a' = min(a-p%a, p%a), so a'<=a/2, therefore, the final time complexity is <span class=\"tex-span\"><i>O</i>(<i>logn</i>)</span>.</p><p>You can check <a class=\"rated-user user-red\" href=\"/profile/Petr\" title=\"International Grandmaster Petr\">Petr</a> <a href=\"//codeforces.com/contest/346/submission/4523388\">'s solution</a> for detail.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/346\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/347\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 201 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-4906-8958\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"4906\",\n blogEntryId: \"8903\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+56</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-8958\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/MinakoKojima\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/MinakoKojima\">\n MinakoKojima\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/20/2013 22:19\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/8903#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/8903#comments\">\n 66\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"8974\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (56)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146290\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mohammadrdeh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/47/avatar/91eee3f7a5ec41f6.jpg'/> </a>\n <div><a href=\"/profile/mohammadrdeh\" title=\"Specialist mohammadrdeh\" class=\"rated-user user-cyan\">mohammadrdeh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146290\" href=\"?#comment-146290\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146290\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"14\"\r\n data-commentUserId=\"47\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+14</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146290\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>there is a typo: "... the classical <strong>LCA</strong> problem ..." => <strong>LCS</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146290 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146290 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146290\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146291\" commentParentId=\"146290\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 01:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146291\" href=\"?#comment-146291\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146290\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146291\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146291\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you. Fixed. m(_ _)m</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146291 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146291 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146291\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146297\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 05:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146297\" href=\"?#comment-146297\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146297\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146297\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Actually our standard solution to C is O(b-a+n). O(b-a+n),O(b-a+nlogn),O((b-a+n)logn) are all able to pass during the test.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146297 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146297 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146297\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146335\" commentParentId=\"146297\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mmaxio\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/486/avatar/4bb53c24fc9e4c1.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/mmaxio\" title=\"International Master mmaxio\" class=\"rated-user user-orange\">mmaxio</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 17:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146335\" href=\"?#comment-146335\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146297\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146335\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146335\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"486\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146335\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>oh, never mind</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146335 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146335 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146335\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146299\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shashwat.gupta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6204/avatar/67f8e17c53f70578.jpg'/> </a>\n <div><a href=\"/profile/shashwat.gupta\" title=\"Specialist shashwat.gupta\" class=\"rated-user user-cyan\">shashwat.gupta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146299\" href=\"?#comment-146299\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146299\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"6204\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146299\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Problem B: Can you Explain little bit more on How "Aho-Corasick automation, or KMP" can help in figuring out smallest string that does not contain virus.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146299 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146299 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146299\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146300\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146300\" href=\"?#comment-146300\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146300\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146300\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For B, I already had the intuitive idea that this problem will be solved by either Aho-Corasick algorithm or KMP with dp, but I could not formalize the idea of states transition in dp. Could you please just provide the state in your dp algorithm?? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146300 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146300 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146300\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146354\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146354\" href=\"?#comment-146354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146354\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Original problem can be solved by dp with two parameters DP[Len(s)] [Len(t)]. <a href=\"https://en.wikipedia.org/wiki/Longest_common_subsequence_problem\">http://en.wikipedia.org/wiki/Longest_common_subsequence_problem</a></p><p>To solve B you need to modificate it to DP[Len(s)][Len(t)][Len(virus)-1] where third parameter means maximum length of suffix of LCS that equal to prefix of virus.</p><p>To easy check where we go from K state (third parameter) by character C we can make automat on prefix function by virus.</p><p>Then if we stand in DP[i][j][k] :<br /> 1) if(s[i] == t[j] and Automat[k][c]<Len(virus) we try to relax DP[i+1][j+1][Automat[k][c]]<br /> 2) Try to relax DP[i][j+1][k] and DP[i+1][j][k]</p><p><strong>UPD</strong> My solution: <a href=\"//codeforces.com/contest/346/submission/4532899\">http://codeforces.com/contest/346/submission/4532899</a> (hope it understandable)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146354\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146357\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 22:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146357\" href=\"?#comment-146357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>got it, many thanks to you man :) Also understood why KMP tag mentioned in the problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146357\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146493\" commentParentId=\"146354\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lama\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/72190/avatar/735906a91d1576e3.jpg'/> </a>\n <div><a href=\"/profile/lama\" title=\"Expert lama\" class=\"rated-user user-blue\">lama</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 18:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146493\" href=\"?#comment-146493\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146354\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146493\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146493\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) Can you please explain what "maximum length of suffix of LCS that equal to prefix of virus" means? 2) What is an automat?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146493 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146493 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146493\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146519\" commentParentId=\"146493\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/EarlOfDitches\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/27174/avatar/6d0644896d8c9a1a.jpg'/> </a>\n <div><a href=\"/profile/EarlOfDitches\" title=\"Master EarlOfDitches\" class=\"rated-user user-orange\">EarlOfDitches</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/25/2013 05:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146519\" href=\"?#comment-146519\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146493\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146519\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146519\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"27174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146519\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>1) We stand in DP[i][j][k]-state (in which we store longest LCS), virus = "virus" <br /> Let's go from k = 0 to 4,then:</p> <pre><code>0) DP[i][j][0] means that finded LCS not ends on "v" or "vi" or "vir" or "viru" or "virus". (example: "a")\n\n1) DP[i][j][1] means that finded LCS ends on "v", but not on "vi" or "vir" or "viru" or "virus". (example: "av")\n\n2) DP[i][j][2] means that finded LCS ends on "vi", but not on "vir" or "viru" or "virus". (example: "avi")\t\n\n3) DP[i][j][3] means that finded LCS ends on "vir", but not on "viru" or "virus". (example: "avir")\n\n4) DP[i][j][4] means that finded LCS ends on "viru", but not on "virus". (example: "aviru")\n\nWe take "longest suffix of LCS that equal prefix of virus", because virus could be: "vvvvv" or "ababv" (and infinite others)\n If LCS = "avvv" - it ends on "v","vv","vvv". (virus = "vvvvv")\n If LCS = "aabab" - it ends on "ab" and "abab". (virus = "ababv")\n</code></pre><p><a href=\"https://en.wikipedia.org/wiki/Knuth%E2%80%93Morris%E2%80%93Pratt_algorithm\">KMP</a></p><p>2) <a href=\"https://en.wikipedia.org/wiki/Automata_theory\">http://en.wikipedia.org/wiki/Automata_theory</a></p><p>Can't find nothing about automaton on prefix-function in english. I hope you will be able understand <a href=\"http://e-maxx.ru/algo/prefix_function\">this</a> with some translator (google translate for example).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146519 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146519 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146519\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"551712\" commentParentId=\"146519\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/srv_twry\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/447741/avatar/d1a80b00eb029c2b.jpg'/> </a>\n <div><a href=\"/profile/srv_twry\" title=\"Expert srv_twry\" class=\"rated-user user-blue\">srv_twry</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/19/2019 12:58\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-551712\" href=\"?#comment-551712\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146519\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"551712\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"447741\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-551712\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Fortunately, the e-maxx article on Prefix function has been translated in English and can be found here: <a href=\"https://cp-algorithms.com/string/prefix-function.html#toc-tgt-12\">prefix-function: automaton on prefix-function</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-551712 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-551712 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-551712\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"768401\" commentParentId=\"146300\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ttbbnnn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1694563/avatar/ff85df0301cf6f76.jpg'/> </a>\n <div><a href=\"/profile/ttbbnnn\" title=\"Master ttbbnnn\" class=\"rated-user user-orange\">ttbbnnn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2021 20:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-768401\" href=\"?#comment-768401\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146300\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"768401\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1694563\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-768401\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My solution for B got a WA on test 41 and I don't know why :<, please help me with this code: <a href=\"https://codeforces.com/contest/346/submission/109283664\">https://codeforces.com/contest/346/submission/109283664</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-768401 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-768401 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-768401\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146301\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 07:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146301\" href=\"?#comment-146301\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146301\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146301\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146301\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"So the remians work is to delete those same xi, and watch out some situation could cause degeneration. Many of us failed in this last step and got TLE", I really could not understand this. What you you mean by degeneration in this case? Please explain this last important step.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146301 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146301 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146301\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146302\" commentParentId=\"146301\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CMHJT\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60974/avatar/719d17962f6861c.jpg'/> </a>\n <div><a href=\"/profile/CMHJT\" title=\"Candidate Master CMHJT\" class=\"rated-user user-violet\">CMHJT</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:37\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146302\" href=\"?#comment-146302\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146301\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146302\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60974\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146302\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>suppose b=1, all x[i]>a, what will happen?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146302 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146302 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146302\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146304\" commentParentId=\"146302\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 08:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146304\" href=\"?#comment-146304\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146302\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146304\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146304\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As b = 1, All x[i] > a. Then a % x[i] = a. So if we take this, then we will lead to a — a = 0, which is less than b. So we need to move one by one, so answer would be a.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146304 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146304 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146304\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146309\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146309\" href=\"?#comment-146309\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146309\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146309\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Alice and Bob problem how do you prove that you will always get {d, 2d, 3d, ... max{xi}} in the end. It is easy to see but I am unable to prove it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146309 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146309 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146309\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146365\" commentParentId=\"146309\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marat.snowbear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98082/avatar/1499cf6d0c86172.jpg'/> </a>\n <div><a href=\"/profile/marat.snowbear\" title=\"International Master marat.snowbear\" class=\"rated-user user-orange\">marat.snowbear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146365\" href=\"?#comment-146365\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146309\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146365\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"98082\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146365\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I convinced myself like this:</p> <ol> <li>Prove that we will be able to get d by some sequence of subtractions.</li> <li>Prove that we will be able to generate {d, 2d, 3d, ...}</li> <li>Prove that we will not be able to get anything else except for { d, 2d, 3d, ... }</li> </ol><p>In details:</p> <ol> <li><p>See <a href=\"https://en.wikipedia.org/wiki/Euclidean_algorithm\">Euclidean algorithm for finding GCD</a>. If you will look into the description or code you will see that it does exactly what is asked in this problem — subtracts numbers one from another. And the result is GCD of original two numbers. So you can see that by some sequence of subtractions you can get GCD.</p></li> <li><p>If you already have d which GCD of all the numbers then you can easily fill all the gaps in { d, 2d, 3d, ..., max } sequence by starting subtracting d from { max, max — d, max — 2d, ... }. So you will get the intended set.</p></li> <li><p>You cannot subtract two numbers a and b which have GCD(a, b) = d and get result which won't be dividable by d. So if you start with set where every numbers can be divided by d then no matter what you subtract you will always have the result which is also dividable by d.</p></li> </ol></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146365 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146365 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146365\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146390\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sachinr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/127206/avatar/e988fa2f7a0714d3.jpg'/> </a>\n <div><a href=\"/profile/sachinr\" title=\"Specialist sachinr\" class=\"rated-user user-cyan\">sachinr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 16:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146390\" href=\"?#comment-146390\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146390\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"127206\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146390\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, got it. Thanks!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146390 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146390 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146390\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"774539\" commentParentId=\"146365\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Focus_2000\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1646716/avatar/b7940b83488f66cf.jpg'/> </a>\n <div><a href=\"/profile/Focus_2000\" title=\"Expert Focus_2000\" class=\"rated-user user-blue\">Focus_2000</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/25/2021 20:24\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-774539\" href=\"?#comment-774539\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146365\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"774539\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1646716\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-774539\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-774539 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-774539 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-774539\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146310\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i_coder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i_coder\" title=\"Expert i_coder\" class=\"rated-user user-blue\">i_coder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 10:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146310\" href=\"?#comment-146310\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146310\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"41979\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146310\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Is this the final editorial (except the D problem) ? The explanations to problems B and C are very limited and not at all well elaborated.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146310 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146310 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146310\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146314\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146314\" href=\"?#comment-146314\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146314\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146314\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can you tell me that why the number of rounds in Problem A will be max(xi)/d-n ? How do you come to this point ? can you please tell me this as am not to figure out this thing ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146314 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146314 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146314\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146316\" commentParentId=\"146314\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 11:45\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146316\" href=\"?#comment-146316\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146314\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146316\" revisionCount=\"7\" revision=\"7\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">7</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146316\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146316\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>take example <br /> 3 9 54 <br /> gcd (3, 9, 54) = 3 <br /> Now total rounds possible including (3, 9, 54) =<br />all multiples of 3 upto 54 <br /> 3, 6, 9, 12, 15, 18 ... 54 <br /> </p><p>So total count of these numbers = 54 / 3 = 18. <br /> </p><p>Now as out of these numbers 3 numbers are already taken, so subtract 3 <br /> so rounds remaining = 18 — 3 = 15 </p><p>Now it is very easy to generalize for 3 being d and 54 being n</p><p>answer would be n / d — n. <br /> I hope it is clear now :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146316 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146316 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146316\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146319\" commentParentId=\"146316\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146319\" href=\"?#comment-146319\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146316\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146319\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146319\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes, it is more clear to me now. but one thing is that how did you approach to gcd thing ? I understood the problem, the logic and all. how did you approach that it will be done using gcd thing and all ? thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146319 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146319 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146319\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146322\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146322\" href=\"?#comment-146322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146322\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My Ideas during solving the problem: <br /> all the examples had gcd 1. So I directly thought answer as max(xi) — n. <br /> But I thought it can not be too simple, I need to think more. <br /> So I took a case 2 4 6, I immediately found I am wrong in this case. <br /> Then the idea came into mind that if gcd of numbers is g. then we can not create any number not divisible by g because (g *k1 — k * k2) = g * (k1 — k2). </p><p>So Finally I coded it and got accpeted :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146322\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146338\" commentParentId=\"146319\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 19:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146338\" href=\"?#comment-146338\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146319\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146338\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146338\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>given the numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>, what is the minimum positive value you can achieve by combining them? </p><p>Let's write down the equation: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>·<i>x</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub>·<i>x</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>n</i></sub>·<i>x</i><sub class=\"lower-index\"><i>n</i></sub> = <i>d</i></span>, where <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> are some unknown integers. </p><p>It is, as you can see, none other than linear Diophantine equation. And it is known there is no solutions if <span class=\"tex-span\"><i>d</i></span> is not a multiple of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span> </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146338 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146338 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146338\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146317\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/subway\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123924/avatar/706e86f587cbabf0.jpg'/> </a>\n <div><a href=\"/profile/subway\" title=\"Expert subway\" class=\"rated-user user-blue\">subway</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146317\" href=\"?#comment-146317\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146317\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146317\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@hellodear-the final set will contain all elements {d,2d,3d,..max(Xi)} (d=gcd of all elements) so total no. of elements in final set =max(Xi)/d since initially we have 'n' elements total no. of new elements to be added in set to make it complete=(max(Xi)/d)-n.. hope this helps you..:)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146317 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146317 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146317\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146320\" commentParentId=\"146317\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hellodear\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/64076/avatar/8f6c8d3f4f2636c1.jpg'/> </a>\n <div><a href=\"/profile/hellodear\" title=\"Pupil hellodear\" class=\"rated-user user-green\">hellodear</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146320\" href=\"?#comment-146320\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146317\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146320\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"64076\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146320\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in this thing, I was applying some game theory, but it doesn't include anything like that. when the question says optimally, then how do you form examples so as to test your code on them ? because optimally means in the best they can. can you elaborate ? thanks to you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146320 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146320 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146320\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146324\" commentParentId=\"146320\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PraveenDhinwa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21525/avatar/90c91732411201a0.jpg'/> </a>\n <div><a href=\"/profile/PraveenDhinwa\" title=\"Expert PraveenDhinwa\" class=\"rated-user user-blue\">PraveenDhinwa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146324\" href=\"?#comment-146324\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146320\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146324\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146324\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"21525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146324\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>optimality argument is simple and also given in the editorial itself. <br /> As total you numbers finally would be {d, 2 * d,, .,, max (xi)}. <br /> Hence whatever you add to the these set, no other person will be able to add that as he has to add a new number everytime to this test. <br /> So outcome depend on the parity of turns.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146324 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146324 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146324\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146325\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sinamosavi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/87557/avatar/bde58fa97bcc5eb0.jpg'/> </a>\n <div><a href=\"/profile/sinamosavi\" title=\"Pupil sinamosavi\" class=\"rated-user user-green\">sinamosavi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 12:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146325\" href=\"?#comment-146325\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146325\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"87557\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146325\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the complete proof for A.Div1 is not that much straightforward. Maybe I'm making it too much difficult, but this is my complete proof:</p><p>First by induction, we prove that the numbers in the end will be <span class=\"tex-span\"><i>a</i>, 2<i>a</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Let <span class=\"tex-span\"><i>g</i> = <i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ... , <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span>. It's trivial that in the end <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>. Assume that <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≥ <i>g</i></span>, because our numbers will be <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), 2<i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>), ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>, so we would have a new gcd. That's a contradiction, so <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) = <i>g</i></span> and our numbers will be <span class=\"tex-span\"><i>g</i>, 2<i>g</i>, ... , <i>max</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. Each move adds one number and in the end there will be <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e6ac12549498d8aaad3d63270d12497bc74a9f84.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> numbers, so the answer wil be the parity of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/48ba1bfd0fa315ab1595947b8e046b4cc211b908.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Sorry for my bad English.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146325 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146325 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146325\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146332\" commentParentId=\"146325\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146332\" href=\"?#comment-146332\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146325\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146332\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-13\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146332\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What about this test <code>2 3 5</code>? <span class=\"tex-span\"><i>min</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) ≠ <i>gcd</i></span></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146332 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146332 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146332\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146333\" commentParentId=\"146332\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 15:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146333\" href=\"?#comment-146333\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146332\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146333\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146333\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Oops. You've meant that <span class=\"tex-span\"><i>a</i></span> — is the result. Sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146333 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146333 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146333\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146334\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 16:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146334\" href=\"?#comment-146334\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146334\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146334\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146334\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>But how to prove that there is always a way to choose <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> while the number of the current round less than the maximum number of rounds? (Div2C)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146334 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146334 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146334\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146339\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:22\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146339\" href=\"?#comment-146339\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146339\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146339\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146339\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If gcd{xi}＝1, then for every xi there must exist ti to make sum｛xi*ti｝＝1. </p><p>(For example, x1＝5,x2＝7,then t1＝3,t2＝-2.x1*t1＋x2*t2＝1.)</p><p>And sum{xi*ti} can be performed in a few turns. ( (5-(7-5))-(7-5). )</p><p>And if we can get 1, then what number between [1,max{xi}] can't we get？</p><p>if gcd{xi}≠1.the proof is similar.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146339 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146339 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146339\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146341\" commentParentId=\"146339\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 20:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146341\" href=\"?#comment-146341\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146339\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146341\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146341\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why there is must exist such t[i]?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146341 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146341 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146341\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146366\" commentParentId=\"146341\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 02:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146366\" href=\"?#comment-146366\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146341\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146366\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146366\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You must know if gcd(a,b)＝1, there must exist x and y to make ax＋by＝1. It can be proved from this.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146366 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146366 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146366\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146376\" commentParentId=\"146334\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146376\" href=\"?#comment-146376\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146334\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146376\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146376\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146376\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So.. If we divide all the numbers by GCD, and after that a pair of coprime numbers have appeared, we always can reach 1. Let's choose coprime <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, then <span class=\"tex-span\">|<i>x</i> - <i>y</i>|</span> will be also coprime with <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>, and it will be less then <span class=\"tex-span\"><i>max</i>(<i>x</i>, <i>y</i>)</span>. So we can choose <span class=\"tex-span\"><i>mid</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>x</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>min</i>(<i>x</i>, |<i>x</i> - <i>y</i>|, <i>y</i>) = <i>y</i><sub class=\"lower-index\">1</sub></span>, and they are coprime, and <span class=\"tex-span\">|<i>x</i><sub class=\"lower-index\">1</sub> - <i>y</i><sub class=\"lower-index\">1</sub>|</span> will be less than <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>. And etc. by induction. But what to do if there is not a pair of coprime numbers after dividing by GCD? For example <code>35 45 63</code>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146376 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146376 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146376\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146404\" commentParentId=\"146376\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mayukuner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/123959/avatar/9dab08ac262f08b8.jpg'/> </a>\n <div><a href=\"/profile/mayukuner\" title=\"Candidate Master mayukuner\" class=\"rated-user user-violet\">mayukuner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146404\" href=\"?#comment-146404\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146376\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146404\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146404\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"123959\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146404\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>63*2＋45*5＋35*(-10)＝1</p><p>Because gcd (35,45)＝5, we can consider 35 and 45 as one number 5x. Because gcd(5,63)＝1, so there must exist x,y to make 5x＋63y＝1.</p><p>So here comes a tragedy. We can get 5 first. Then we use this number together with 63 to make 1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146404 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146404 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146404\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146346\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KiAsaGibona\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/KiAsaGibona\" title=\"Specialist KiAsaGibona\" class=\"rated-user user-cyan\">KiAsaGibona</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/21/2013 21:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146346\" href=\"?#comment-146346\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146346\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146346\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"99053\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146346\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Someone please explain the greedy idea of (Div 1 C) (Number Transformation II). Thanks in advance :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146346 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146346 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146346\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146367\" commentParentId=\"146346\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 09:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146367\" href=\"?#comment-146367\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146346\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146367\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146367\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's a pretty simple greedy idea: Just pick the <code>x</code> that makes the value of <code>a</code> smallest after applying the operation <code>a = a - a%x</code> (or subtract 1 if no choice for <code>x</code> makes <code>a</code> smaller). The proof why this works is given in the editorial: it is never better to get a larger number, so you should get the smallest one you can.</p><p>As listed on the last paragraph of the editorial you have to be careful to remove all <code>x</code> that are either duplicates or cannot be used anymore (<code>a - (a%x)</code> is smaller than <code>b</code>), otherwise you will get TLE.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146367 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146367 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146367\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146382\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146382\" href=\"?#comment-146382\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146382\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146382\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146382\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>how to find this x for each number?</p><p>we will iterate on all x[i]s and only delete x[i]s when x[i] > a?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146382 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146382 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146382\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146405\" commentParentId=\"146382\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ffao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34538/avatar/60e02a3edaa69678.jpg'/> </a>\n <div><a href=\"/profile/ffao\" title=\"International Grandmaster ffao\" class=\"rated-user user-red\">ffao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 18:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146405\" href=\"?#comment-146405\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146382\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146405\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34538\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146405\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Iterate through all x[i]s and delete them when a — (a%x[i]) is smaller than b (if you only delete when x[i] > a, you will also get TLE).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146405 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146405 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146405\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146625\" commentParentId=\"146367\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 17:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146625\" href=\"?#comment-146625\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146367\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146625\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146625\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm really striving to understand why the algorithm turns out to be linear instead of quadratic... I know the editorial says "That is because, we could cut exactly <span class=\"tex-span\"><i>max</i>{<i>xi</i>}</span> in each 2 step.", but I can't really get what it means :\\</p><p>Can you give me a hint? Thanks :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146625 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146625 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146625\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146643\" commentParentId=\"146625\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/xenoslash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88090/avatar/f75f8cbc20d6133f.jpg'/> </a>\n <div><a href=\"/profile/xenoslash\" title=\"Expert xenoslash\" class=\"rated-user user-blue\">xenoslash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2013 19:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146643\" href=\"?#comment-146643\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146625\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"146643\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"146643\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"88090\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146643\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have an easy intuition of cutting at least max{xi} in O(1) steps, not sure what was the intended 2 step proofs though. I am going to use xi to refer to max{xi}, and assume that proper care is taken to only keep the relevant xi's.</p><p>When we do a-(a % xi), we bring caused a to be the next largest integer <= a that is a multiple of xi, since now new_a % xi = 0. Then, if a is divisible by xi, you can do.., do a-1 (causing it to be non-divisible by xi), then finally a-(a%xi) again. In this 3 step sequence you have brought a down to the next lower multiple of xi, and have essentially cut max{xi} in O(1) number of steps.</p><p>Sample code : <a href=\"//codeforces.com/contest/346/submission/4545367\">http://codeforces.com/contest/346/submission/4545367</a> Yeah I used tree set so it's not exactly O(n).. but hash set keeps giving me TLE :(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146643 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146643 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146643\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146689\" commentParentId=\"146643\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/obag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31489/avatar/a49e6d79203475b7.jpg'/> </a>\n <div><a href=\"/profile/obag\" title=\"Candidate Master obag\" class=\"rated-user user-violet\">obag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2013 12:31\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146689\" href=\"?#comment-146689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146643\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"31489\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you very much, that was really eye-opening! This is why I love Codeforces, great community! :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146689\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146371\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Corvo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/11909/avatar/8404ac1aff5270ec.jpg'/> </a>\n <div><a href=\"/profile/Corvo\" title=\"Pupil Corvo\" class=\"rated-user user-green\">Corvo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 12:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146371\" href=\"?#comment-146371\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146371\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"11909\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146371\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Please explain why the problem is solved through the GDC (A)? I tried like <a href=\"https://codeforces.com/contest/347/submission/4535232\">this</a>, but I still can not understand why you can not do. Please give a short test on which the decision falls. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146371 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146371 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146371\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146375\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CountZero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/17812/avatar/5d71cc3cc611312.jpg'/> </a>\n <div><a href=\"/profile/CountZero\" title=\"Expert CountZero\" class=\"rated-user user-blue\">CountZero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146375\" href=\"?#comment-146375\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146375\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"17812\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146375\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><pre><code>3\n14 4 2\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146375 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146375 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146375\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146378\" commentParentId=\"146371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akashdeep\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/39866/avatar/6f66d1bbe26ef4ca.jpg'/> </a>\n <div><a href=\"/profile/akashdeep\" title=\"International Master akashdeep\" class=\"rated-user user-orange\">akashdeep</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 13:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146378\" href=\"?#comment-146378\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146378\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"39866\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146378\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Because only those numbers are possible in the game which are multiple of gcd. See this simplest test case</p> <pre><code>2\n4 6\n</code></pre><p>The only number possible in the game is (6-4) i.e. 2, but in your code u are assuming that somehow these (1,2,3,5) numbers can be obtained which is a wrong assumption.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146378 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146378 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146378\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146408\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/NegaTeeF\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/NegaTeeF\" title=\"Master NegaTeeF\" class=\"rated-user user-orange\">NegaTeeF</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 20:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146408\" href=\"?#comment-146408\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146408\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"65829\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146408\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Explain please, how to do Div1-D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146408 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146408 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146408\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146410\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/irakli_p\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29034/avatar/d879a3156498c6c7.jpg'/> </a>\n <div><a href=\"/profile/irakli_p\" title=\"Expert irakli_p\" class=\"rated-user user-blue\">irakli_p</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/22/2013 21:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146410\" href=\"?#comment-146410\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146410\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29034\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146410\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i didn't understand Div 2 — D can someone explain it to me please </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146410 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146410 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146410\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146443\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/suiyuan2009\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49923/avatar/9065a92c0b30b883.jpg'/> </a>\n <div><a href=\"/profile/suiyuan2009\" title=\"Master suiyuan2009\" class=\"rated-user user-orange\">suiyuan2009</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 13:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146443\" href=\"?#comment-146443\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146443\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49923\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146443\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>problem B,ac automachine is doing the thing that belong to kmp</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146443 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146443 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146443\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146452\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 17:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146452\" href=\"?#comment-146452\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146452\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146452\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div1_E: Should the "Doodler" jump over the platform which H = P ? I just confused about that.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146452 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146452 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146452\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146480\" commentParentId=\"146452\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bool_kzf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/68488/avatar/2ef13487f2d6b84.jpg'/> </a>\n <div><a href=\"/profile/bool_kzf\" title=\"Master bool_kzf\" class=\"rated-user user-orange\">bool_kzf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/24/2013 11:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146480\" href=\"?#comment-146480\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146452\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146480\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"68488\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146480\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OK I got the answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146480 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146480 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146480\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"146463\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2013 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-146463\" href=\"?#comment-146463\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"146463\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"44\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+44</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-146463\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>still waiting for D tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-146463 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-146463 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-146463\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147566\" commentParentId=\"146463\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/05/2013 05:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147566\" href=\"?#comment-147566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-146463\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>.. Update .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147566\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"235917\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/saurabhverma\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/143428/avatar/48808a8d5db775d4.jpg'/> </a>\n <div><a href=\"/profile/saurabhverma\" title=\"Expert saurabhverma\" class=\"rated-user user-blue\">saurabhverma</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2015 20:05\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-235917\" href=\"?#comment-235917\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"235917\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"143428\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-235917\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In my approach to problem div1 B, I calculated longest common subsequence, prepended virus to it, calculated the Z function and deleted every character which had z[i] >= virus.size(). I don't think my approach is wrong. Can someone tell me if my code is wrong or the approach has some flaw. Thanks. Submission : <a href=\"//codeforces.com/contest/346/submission/11491420\">http://codeforces.com/contest/346/submission/11491420</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-235917 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-235917 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-235917\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"530287\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arpit4427\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/717924/avatar/90dcbc94a1e57cf.jpg'/> </a>\n <div><a href=\"/profile/arpit4427\" title=\"Expert arpit4427\" class=\"rated-user user-blue\">arpit4427</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/26/2019 14:04\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-530287\" href=\"?#comment-530287\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"530287\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"530287\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"717924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-530287\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone explain how to solve this problem <a href=\"/contest/346/problem/B\" title=\"Codeforces Round 201 (Div. 1)\">346B - Lucky Common Subsequence</a>? I have went thorugh the editorial but I could not understand.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-530287 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-530287 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-530287\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-8974\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview8974 = true;\r\nvar lastPreviewContent8974 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=8974] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=8974] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-8958\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 8958, _tta: Codeforces.tta(), topicRevisionId: 32357, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:12:24</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812874998e81759f',t:'MTY5NjcwNTk0NS4wMjkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1757,"cells":{"problem_id":{"kind":"string","value":"348A"},"contest":{"kind":"string","value":"348"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Mafia"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Mafia</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>One day <span class=\"tex-span\"><i>n</i></span> friends gathered together to play \"Mafia\". During each round of the game some player must be the supervisor and other <span class=\"tex-span\"><i>n</i> - 1</span> people take part in the game. For each person we know in how many rounds he wants to be a player, not the supervisor: the <span class=\"tex-span\"><i>i</i></span>-th person wants to play <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> rounds. What is the minimum number of rounds of the \"Mafia\" game they need to play to let each person play at least as many rounds as they want?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(3 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span> — the <span class=\"tex-span\"><i>i</i></span>-th number in the list is the number of rounds the <span class=\"tex-span\"><i>i</i></span>-th person wants to play.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print a single integer — the minimum number of game rounds the friends need to let the <span class=\"tex-span\"><i>i</i></span>-th person play at least <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> rounds.</p><p>Please, do not use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in С++. It is preferred to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>3 2 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>2 2 2 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>You don't need to know the rules of \"Mafia\" to solve this problem. If you're curious, it's a game Russia got from the Soviet times: <span class=\"tex-font-style-tt\">http://en.wikipedia.org/wiki/Mafia_(party_game)</span>.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"8607d6fc8fd602788ef41d402c35387c\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"c986f3ff2f9571024a91a4a1006fb9ec8f2a6679\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='8607d6fc8fd602788ef41d402c35387c'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F348%2Fproblem%2FA%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='8607d6fc8fd602788ef41d402c35387c'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox highlight-blue sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Attention\n <div class=\"top-links\">\n </div>\n </div>\n <div style=\"margin: 1em\">\r\n The package for this problem was not updated by the problem writer or Codeforces administration after we've upgraded the judging servers. To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/348\">Codeforces Round 202 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='8607d6fc8fd602788ef41d402c35387c'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/348/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Binary search\">\r\n binary search\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Sortings, orderings\">\r\n sortings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1600\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='8607d6fc8fd602788ef41d402c35387c'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3551\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='8607d6fc8fd602788ef41d402c35387c'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"3551\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/8985\" title=\"Codeforces Round #202\" target=\"_blank\">Codeforces Round #202</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1879:1880\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/9031\" title=\"Editorial for Codeforces Round #202\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1937:1938\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/348\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/348/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/348/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/348/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/348/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/348/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/348/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/348/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_cf7da5aa8b010229abc6bd8644c7fdfcea507ce6\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Mafia</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>One day <span class=\"tex-span\"><i>n</i></span> friends gathered together to play "Mafia". During each round of the game some player must be the supervisor and other <span class=\"tex-span\"><i>n</i> - 1</span> people take part in the game. For each person we know in how many rounds he wants to be a player, not the supervisor: the <span class=\"tex-span\"><i>i</i></span>-th person wants to play <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> rounds. What is the minimum number of rounds of the "Mafia" game they need to play to let each person play at least as many rounds as they want?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(3 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span> — the <span class=\"tex-span\"><i>i</i></span>-th number in the list is the number of rounds the <span class=\"tex-span\"><i>i</i></span>-th person wants to play.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print a single integer — the minimum number of game rounds the friends need to let the <span class=\"tex-span\"><i>i</i></span>-th person play at least <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> rounds.</p><p>Please, do not use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in С++. It is preferred to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />3 2 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />2 2 2 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>You don't need to know the rules of "Mafia" to solve this problem. If you're curious, it's a game Russia got from the Soviet times: <span class=\"tex-font-style-tt\">http://en.wikipedia.org/wiki/Mafia_(party_game)</span>.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:34:00</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122be1589837c17',t:'MTY5NjY0NjA0MC4wNjMwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Binary search\", \"Mathematics including integration, differential equations, etc\", \"Sortings, orderings\"]"},"short_tags":{"kind":"string","value":"[\"binary search\", \"math\", \"sortings\", \"*1600\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/9031"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"cb06d236ed9a46e8f0786c3a8982ef49\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Editorial for Codeforces Round #202 - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Editorial for Codeforces Round #202 - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='cb06d236ed9a46e8f0786c3a8982ef49'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F9031\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='cb06d236ed9a46e8f0786c3a8982ef49'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:34</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:52:34</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='cb06d236ed9a46e8f0786c3a8982ef49'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/caustique\">caustique</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/caustique\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/caustique\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/caustique\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/caustique\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/caustique\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/caustique\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/caustique\" style=\"text-decoration:none;color:black !important;\">caustique's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"9086\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/9031\"> <p>Editorial for Codeforces Round #202</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/caustique\" title=\"Specialist caustique\" class=\"rated-user user-cyan\">caustique</a>,\r\n <span class=\"format-humantime\" title=\"Sep/30/2013 17:30\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"/contest/349/problem/A\" title=\"Codeforces Round 202 (Div. 2)\">349A - Cinema Line</a></h3><p>In the problem you need to decide whether cashier can give a change to all customers if the price of the ticket is 25 rubles and there's 3 kinds of bills: 25, 50 and 100 rubles. There's no money in the ticket office in the beginning.</p><p>Let's consider 3 cases.</p> <ul> <li>Customer has 25 rubles hence he doesn't need a change.</li> <li>Customer has 50 rubles hence we have to give him 25 rubles back.</li> <li>Customer has 100 rubles hence we need to give him 75 rubles back. It can be done in 2 ways. 75=25+50 и 75=25+25+25. Notice that it's always worth to try 25+50 first and then 25+25+25. It's true because bills of 25 rubles can be used both to give change for 50 and 100 rubles and bills of 50 rubles can be used only to give change for 100 rubles so we need to save as much 25 ruble bills as possible.</li> </ul><p>The solution is to keep track of the number of 25 and 50 ruble bills and act greedily when giving change to 100 rubles — try 25+50 first and then 25+25+25.</p><h3><a href=\"/contest/349/problem/B\" title=\"Codeforces Round 202 (Div. 2)\">349B - Color the Fence</a></h3><p>In the problem you're asked to write the largest possible number given number of paint that you have and number of paint that you need to write each digit.</p><p>Longer number means larger number so it's worth to write the longest possible number. Because of that we choose the largest digit among those that require the least number of paint. Let the number of paint for that digit <span class=\"tex-span\"><i>d</i></span> be equal to <span class=\"tex-span\"><i>x</i></span>, and we have <span class=\"tex-span\"><i>v</i></span> liters of paint total. Then we can write number of the length <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5bd96efe8d1b2b6f325a8e21120da5b7fb1d569b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Now we know the length of the number, let it be <span class=\"tex-span\"><i>len</i></span>. Write down temporary result – string of length <span class=\"tex-span\"><i>len</i></span>, consisting of digits <span class=\"tex-span\"><i>d</i></span>. We have supply of <span class=\"tex-span\"><i>v</i>–<i>len</i>·<i>x</i></span> liters of paint. In order to enhance the answer, we can try to update the number from the beginning and swap each digit with the maximal possible. It's true because numbers of the equal length are compared in the highest digits first. Among digits that are greater than current we choose one that we have enough paint for and then update answer and current number of paint.</p><p>If the length of the answer is 0 then you need to output -1.</p><h3><a href=\"/contest/348/problem/A\" title=\"Codeforces Round 202 (Div. 1)\">348A - Mafia</a></h3><p>In the problem you need to find out how many games you need to play in order to make all people happy. It means that each of them played as many games as he wanted.</p><p>Let the answer be <span class=\"tex-span\"><i>x</i></span> games. Notice that <span class=\"tex-span\"><i>max</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, …, <i>a</i><sub class=\"lower-index\"><i>n</i></sub>) ≤ <i>x</i></span>. Then <span class=\"tex-span\"><i>i</i></span>-th player can be game supervisor in <span class=\"tex-span\"><i>x</i>–<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> games. If we sum up we get <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/273983d50c7770b3d057afda9089d2c7bde493b7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> — it's the number of games in which players are ready to be supervisor. This number must be greater or equal to <span class=\"tex-span\"><i>x</i></span> — our answer.</p> <center> <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0d099a78acb244b51f728a99f3c6b8187f6e5cda.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> <br /><br /> <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/dbad061b1770e0f3a9a4eea1ead7aa749f03411f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> <br /><br /> <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7cfb7254c48a7b9e88acc46e80426625bb9cf856.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> <br /><br /> <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/ed9087651fa74f3b679f71c947bd77a1b5567e86.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>Don't forget about that condition: <span class=\"tex-span\"><i>max</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, …, <i>a</i><sub class=\"lower-index\"><i>n</i></sub>) ≤ <i>x</i></span>.</p><h3><a href=\"/contest/348/problem/B\" title=\"Codeforces Round 202 (Div. 1)\">348B - Apple Tree</a></h3><p>In the problem you need to find out minimal number of apples that you need to remove in order to make tree balanced.</p><p>Notice, that if we know the value in the root then we know values in all other vertices. The value in the leaf is equal to the value in the root divided to the product of the powers of all vertices on the path between root and leaf.</p><p>For every vertex let's calculate <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub></span> — minimal number in that vertex (not zero) in order to make tree balanced. For leaves <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub> = 1</span>, for all other vertices <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub></span> is equal to <span class=\"tex-span\"><i>k</i>·<i>lcm</i>(<i>d</i><sub class=\"lower-index\"><i>j</i></sub><sub class=\"lower-index\">1</sub>, <i>d</i><sub class=\"lower-index\"><i>j</i></sub><sub class=\"lower-index\">2</sub>, ..., <i>d</i><sub class=\"lower-index\"><i>j</i></sub><sub class=\"lower-index\"><i>k</i></sub>)</span>, where <span class=\"tex-span\"><i>j</i><sub class=\"lower-index\">1</sub>, <i>j</i><sub class=\"lower-index\">2</sub>, ..., <i>j</i><sub class=\"lower-index\"><i>k</i></sub></span> — sons of the vertex <span class=\"tex-span\"><i>i</i></span>. Let's calculate <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></span> — sum in the subtree of the vertex <span class=\"tex-span\"><i>i</i></span>. All that can be done using one depth first search from the root of the tree.</p><p>Using second depth first search one can calculate for every vertex maximal number that we can write in it and satisfty all conditions. More precisely, given vertex <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>k</i></span> of its sons <span class=\"tex-span\"><i>j</i><sub class=\"lower-index\">1</sub>, <i>j</i><sub class=\"lower-index\">2</sub>, ..., <i>j</i><sub class=\"lower-index\"><i>k</i></sub></span>. Then if <span class=\"tex-span\"><i>m</i> = <i>min</i>(<i>s</i><sub class=\"lower-index\"><i>j</i></sub><sub class=\"lower-index\">1</sub>, <i>s</i><sub class=\"lower-index\"><i>j</i></sub><sub class=\"lower-index\">2</sub>, ..., <i>s</i><sub class=\"lower-index\"><i>j</i></sub><sub class=\"lower-index\"><i>k</i></sub>)</span> and <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7d88ee68f9b5cb6c51b0ffd1be754d7acb6dde5f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> — minimal number, that we can write to the sons of vertex <span class=\"tex-span\"><i>i</i></span>, then it's worth to write numbers <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b1d6b319cafccba369e82104fc0b9340a7511d35.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> to the sons of vertex <span class=\"tex-span\"><i>i</i></span>. Remains <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/756c75f3d034342e2436023bf851ae7c807fe378.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> we add to the answer.</p><h3><a href=\"/contest/348/problem/C\" title=\"Codeforces Round 202 (Div. 1)\">348C - Subset Sums</a></h3><p>This problem is about data structures.</p><p>First step of the solution is to divide sets to heavy and light. Light ones are those that contains less than <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/712f9a224d6c7824add37b6cd766c21f73a40d59.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> elements. All other sets are heavy.</p><p>Key observation is that every light set contains less than <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/712f9a224d6c7824add37b6cd766c21f73a40d59.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> elements and number of heavy sets doesn't exceed <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/712f9a224d6c7824add37b6cd766c21f73a40d59.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> because we have upper bound for sum of the sizes of all sets.</p><p>In order to effectively answer queries, for every set (both light and heavy) we calculate size of the intersection of this set and each heavy set. It can be done with time and memory <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0c18a224e805d960478a53ca7ac5ae33eaed6dd7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. For every heavy set we create boolean array of size <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. In <span class=\"tex-span\"><i>i</i></span>-th cell of this array we store how many elements <span class=\"tex-span\"><i>i</i></span> in given set. Then for each element and each heavy set we can check for <span class=\"tex-span\"><i>O</i>(1)</span> time whether element is in the set.</p><p>Now let's consider 4 possible cases:</p> <ul> <li><p><em>Add to the light set.</em> Traverse all numbers in the set and add the value from the query to each of them. Then traverse all heavy sets and add (size of intersection * the value from the query). Time is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4479908227e8a1d31223f9d311fbed16783002ae.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p></li> <li><p><em>Add to the heavy set.</em> Just update the counter for the heavy set. Time is <span class=\"tex-span\"><i>O</i>(1)</span>.</p></li> <li><p><em>Answer to the query for the light set.</em> Traverse all numbers in the set and add values to the answer. Then traverse all heavy sets and add to the answer (answer for this heavy set * size of intersection with the set in the query). Time is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4479908227e8a1d31223f9d311fbed16783002ae.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p></li> <li><p><em>Answer to the query for the heavy set.</em> Take already calculated answer, then traverse all heavy sets and add (answer for this heavy set * size of intersection with the set in the query). Time is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4479908227e8a1d31223f9d311fbed16783002ae.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p></li> </ul><p>We have <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> queries so total time is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0c18a224e805d960478a53ca7ac5ae33eaed6dd7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><h3><a href=\"/contest/348/problem/D\" title=\"Codeforces Round 202 (Div. 1)\">348D - Turtles</a></h3><p>In the problem you're asked to find the number of pairs of non-intersecting paths between left upper and right lower corners of the grid. You can use following <a href=\"https://en.wikipedia.org/wiki/Lindstr%C3%B6m%E2%80%93Gessel%E2%80%93Viennot_lemma\">lemma</a> for that. Thanks to <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a> for the link. More precisely, considering our problem, this lemma states that given sets of initial <span class=\"tex-span\"><i>A</i> = {<i>a</i>1, <i>a</i>2}</span> and final <span class=\"tex-span\"><i>B</i> = {<i>b</i>1, <i>b</i>2}</span> points, the answer is equal to the following determinant: </p><center> <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d7202e22107a0d46707a9a3013dc605f83d25fa2.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center> where <span class=\"tex-span\"><i>f</i>(<i>x</i>, <i>y</i>)</span> — is equal to the number of paths from point <span class=\"tex-span\"><i>x</i></span> to point <span class=\"tex-span\"><i>y</i></span>. You can calculate this function using dynamic programming.<p>Finally we need to decide what sets of initial and final points we choose. You can take <span class=\"tex-span\"><i>A</i> = {(0, 1), (1, 0)}</span> and <span class=\"tex-span\"><i>B</i> = {(<i>n</i> - 2, <i>m</i> - 1), (<i>n</i> - 1, <i>m</i> - 2)}</span> in order to make paths non-intersecting even in 2 points.</p><h3><a href=\"/contest/348/problem/E\" title=\"Codeforces Round 202 (Div. 1)\">348E - Pilgrims</a></h3><p>Let’s build a simple solution at first and then we will try to improve it to solve problem more effectively given the constraints.</p><p>For every vertex let’s find the list of the farthest vertices. Let’s find vertices on the intersection of the paths between current vertex and each vertex from the list that don’t contain monasteries. If we remove any of these vertices then every vertex from the list is unreachable from the current monastery. For every vertex from the intersection increment the counter. Then the answer for the problem is the maximum among all counters and the number of such maxima.</p><p>Let’s solve the problem more effectively using the same idea. Let’s make the tree with root. For every vertex we will find the list of the farthest vertices only in the subtree. While traversing the tree using depth first search we return the largest depth in the subtree and the number of the vertex where it was reached. Among all of the sons of the current vertex we choose the maximum of depths. If maximum is reached one time then we return the same answer that was returned from the son. If the answer was reached more than one time then we return the number of the current vertex. Essentially, we find LCA of the farthest vertices according to the current vertex. Before quitting the vertex we increment the values on the segment between current vertex and found LCA. One can use Eulerian tour and segment tree for adding on the segment.</p><p>Finally, the last stage of solving the problem – to solve it for the case when the farthest vertex is not in the subtree of the current vertex. For solving of that subproblem we use the same idea that was used in the problem of the finding the maximal path in the tree. For every vertex we keep 3 maximums – 3 farthest vertices in the subtree. When we go down to the subtree, we pass 2 remaining maximums too. In that way, when we’re in any vertex, we can decide whether there’s a path not in the subtree (it means, going up) of the same or larger length. If there’re 2 paths of the same length in the subtree and not in the subtree, it means that for the pilgrim from the current monastery there’s always a path no matter what town was destroyed. If one of the quantities is larger then we choose the segment in Eulerian tour and increment the value on the segment. The case where there’s several paths (at least 2) out of the subtree of the same maximal length, is the same with the case in the subtree.</p><p>LCA and segment tree can be solved effectively in <span class=\"tex-span\"><i>O</i>(<i>logN</i>)</span> time per query so the total memory and time is <span class=\"tex-span\"><i>O</i>(<i>NlogN</i>)</span>.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/348\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 202 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/349\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 202 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-784-9086\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"784\",\n blogEntryId: \"9031\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces+%23202\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces #202</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=202\" class=\"tag notice\" style=\"text-decoration: none;\">202</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-9086\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+50</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-9086\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/caustique\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/caustique\">\n caustique\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/30/2013 17:30\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/9031#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/9031#comments\">\n 50\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"9102\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (39)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147085\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sillycross\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41652/avatar/58966d0c793c6394.jpg'/> </a>\n <div><a href=\"/profile/sillycross\" title=\"Grandmaster sillycross\" class=\"rated-user user-red\">sillycross</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/01/2013 07:37\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147085\" href=\"?#comment-147085\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147085\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"41652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147085\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very nice idea for problem D. :) It's actually possible to solve problem E in O(n) time. LCA is not necessary, the "counting" process can be done by two dfs, first count the occurences of nodes in the "going up" part of paths, then count the occurences of nodes in the "going down" parts. You may see my solution for detail..</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147085 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147085 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147085\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147098\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/huzecong\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/42728/avatar/4193f30f2ff01521.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/huzecong\" title=\"International Master huzecong\" class=\"rated-user user-orange\">huzecong</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/01/2013 12:05\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147098\" href=\"?#comment-147098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"42728\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>There's actually no need to use binary search in problem C, when finding intersections of sets. A brute-force implementation consumes only <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0c18a224e805d960478a53ca7ac5ae33eaed6dd7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> time.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147098\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147132\" commentParentId=\"147098\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Thomas_Ahle\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/19938/avatar/30f67818e421c7e.jpg'/> </a>\n <div><a href=\"/profile/Thomas_Ahle\" title=\"Candidate Master Thomas_Ahle\" class=\"rated-user user-violet\">Thomas_Ahle</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/01/2013 19:09\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147132\" href=\"?#comment-147132\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-147098\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147132\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"19938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147132\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I still don't get how it's done. There are <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fa4e8e6a3b911ecefd2c2ea71ce3f57ad0fcc02d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> intersections to calculate, and each one takes <span class=\"tex-span\"><i>n</i></span> time.. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147132 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147132 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147132\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147181\" commentParentId=\"147132\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/al13n\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2362/avatar/cd08b84008332431.jpg'/> </a>\n <div><a href=\"/profile/al13n\" title=\"Grandmaster al13n\" class=\"rated-user user-red\">al13n</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/01/2013 22:16\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147181\" href=\"?#comment-147181\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-147132\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147181\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"2362\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147181\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For each element of each set see if it's contained in each big set (storing big sets in boolean arrays). There are N elements in total and <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e13517ff4c4fef8f8f59a599e10028d5eebef947.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> big sets, so it's <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/63364b2e896bd50f82216d1a378bb4c0c0f5f799.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> time and space.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147181 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147181 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147181\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147187\" commentParentId=\"147181\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Thomas_Ahle\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/19938/avatar/30f67818e421c7e.jpg'/> </a>\n <div><a href=\"/profile/Thomas_Ahle\" title=\"Candidate Master Thomas_Ahle\" class=\"rated-user user-violet\">Thomas_Ahle</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/01/2013 22:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147187\" href=\"?#comment-147187\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-147181\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147187\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"19938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147187\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah, that's a nice way to analyze it. And if we use binary search instead of boolean array, it'll be n*sqrtn*logn. But then I don't get the n*sqrtn "brute force" approach. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147187 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147187 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147187\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147234\" commentParentId=\"147187\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/al13n\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2362/avatar/cd08b84008332431.jpg'/> </a>\n <div><a href=\"/profile/al13n\" title=\"Grandmaster al13n\" class=\"rated-user user-red\">al13n</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/02/2013 09:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147234\" href=\"?#comment-147234\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-147187\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147234\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2362\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147234\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I guess <a href=\"./huzecong.html\">huzecong</a> meant boolean arrays for big sets.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147234 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147234 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147234\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147387\" commentParentId=\"147187\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/huzecong\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/42728/avatar/4193f30f2ff01521.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/huzecong\" title=\"International Master huzecong\" class=\"rated-user user-orange\">huzecong</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/04/2013 05:41\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147387\" href=\"?#comment-147387\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-147187\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147387\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"42728\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147387\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry for not being clear, but a boolean array was what I meant... I thought that compared to the binary search approach this one seems pretty "brute-force"...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147387 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147387 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147387\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"180230\" commentParentId=\"147387\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mbrc\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62192/avatar/9a138058cf3f4a38.jpg'/> </a>\n <div><a href=\"/profile/mbrc\" title=\"International Master mbrc\" class=\"rated-user user-orange\">mbrc</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/30/2014 12:59\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-180230\" href=\"?#comment-180230\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-147387\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"180230\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"62192\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-180230\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In the editorial we defined heavy sets to be those which contained <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/ae895c49065dca0d23e5ebfe71aafb4331132363.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> elements. Denoting <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c9b08c452903bc9c76ae70d15f05576da9a98e95.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, we have atmost <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a01d6cf5c7333fabe2c51cd8c6a480afe3e294aa.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> heavy sets. If we go through each element of each set (<span class=\"tex-span\"><i>X</i></span> of those) and check if its contained in every heavy set (<img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/742a0e444c38ae8b83b0a1ce942c6bdbcd3dfd85.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> of those), we have a complexity of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bb21f6242e31840bf429c218b98db6cd4ac40827.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> which is out of limits. Am I missing anything?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-180230 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-180230 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-180230\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"180231\" commentParentId=\"180230\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/I_love_Tanya_Romanova\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/I_love_Tanya_Romanova\" title=\"International Grandmaster I_love_Tanya_Romanova\" class=\"rated-user user-red\">I_love_Tanya_Romanova</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/30/2014 13:20\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-180231\" href=\"?#comment-180231\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-180230\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"180231\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"180231\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"5023\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-180231\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>According to problem statement, <em>It is guaranteed that the sum of sizes of all sets Sk doesn't exceed 10^5.</em> Naive solution works in (10^5)*(10^5)/sqrt(10^5), it is just few hundred millions of operations.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-180231 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-180231 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-180231\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"180232\" commentParentId=\"180231\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mbrc\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62192/avatar/9a138058cf3f4a38.jpg'/> </a>\n <div><a href=\"/profile/mbrc\" title=\"International Master mbrc\" class=\"rated-user user-orange\">mbrc</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/30/2014 13:22\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-180232\" href=\"?#comment-180232\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-180231\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"180232\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"180232\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"62192\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-180232\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><span class=\"tex-span\"><i>X</i> ≤ 10<sup class=\"upper-index\">5</sup></span>, but with small n (like 4), <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c5dd32337c9dea57867c23ed0d9d99e70818c06e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> which is TLE? In the editorial is <span class=\"tex-span\"><i>X</i> = <i>n</i></span> ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-180232 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-180232 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-180232\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"180235\" commentParentId=\"180232\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/I_love_Tanya_Romanova\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/I_love_Tanya_Romanova\" title=\"International Grandmaster I_love_Tanya_Romanova\" class=\"rated-user user-red\">I_love_Tanya_Romanova</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/30/2014 14:02\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-180235\" href=\"?#comment-180235\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-180232\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"180235\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"5023\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-180235\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you'll take heavy_size>=sqrt(X) — it will be ok, right? :) </p><p>I am not sure, but it looks like you are right, taking heavy_size>=sqrt(n) is bad idea.</p><p>But it will pass system tests) It do not proves that this solution is OK, it just shows us that tests are very weak. Take a look at <a href=\"/contest/348/submission/7288633\" title=\"Посылка 7288633 от TsunamiNoLetGo\">7288633</a>, <a class=\"rated-user user-violet\" href=\"/profile/TsunamiNoLetGo\" title=\"Кандидат в мастера TsunamiNoLetGo\">TsunamiNoLetGo</a> has array for heavy sets of size 320 only, and heavy_size>=sqrt(n). It is easy to constuct testcase with 100000 heavy sets — just take n=1, m=100000, and all sets of size 1. But this solution passed, therefore i guess that such cases are missed in testdata.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-180235 en true\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-180235 en true\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-180235\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"180236\" commentParentId=\"180235\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mbrc\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62192/avatar/9a138058cf3f4a38.jpg'/> </a>\n <div><a href=\"/profile/mbrc\" title=\"International Master mbrc\" class=\"rated-user user-orange\">mbrc</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/30/2014 14:06\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-180236\" href=\"?#comment-180236\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-180235\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"180236\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"62192\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-180236\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes thats exactly what I meant. Setting heavy_size >= sqrt(X) is okay with me. SealView also told me that in the messages. He advises to set it to a constant (like 300). Thanks for looking into my problem. :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-180236 en true\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-180236 en true\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-180236\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147102\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AM51\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71971/avatar/70380ed483ba029.jpg'/> </a>\n <div><a href=\"/profile/AM51\" title=\"Pupil AM51\" class=\"rated-user user-green\">AM51</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/01/2013 14:21\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147102\" href=\"?#comment-147102\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147102\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"71971\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147102\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in problem Apple trees can somebody explain the idea of finding intersections of sets using binary search</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147102 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147102 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147102\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147103\" commentParentId=\"147102\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/caustique\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1135/avatar/4fe2a22bc0d3c95d.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/caustique\" title=\"Specialist caustique\" class=\"rated-user user-cyan\">caustique</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/01/2013 14:29\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147103\" href=\"?#comment-147103\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-147102\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147103\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1135\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147103\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think, you're talking about "Subset sums" problem.</p><p>Sort all lists. Iterate over one set and check whether element from this set is in another set. You can do it using binary_search() function from STL.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147103 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147103 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147103\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147115\" commentParentId=\"147103\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AM51\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71971/avatar/70380ed483ba029.jpg'/> </a>\n <div><a href=\"/profile/AM51\" title=\"Pupil AM51\" class=\"rated-user user-green\">AM51</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/01/2013 16:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147115\" href=\"?#comment-147115\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-147103\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147115\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"71971\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147115\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>no apple trees 348B</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147115 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147115 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147115\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147119\" commentParentId=\"147115\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/01/2013 17:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147119\" href=\"?#comment-147119\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-147115\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147119\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147119\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>There is no binary search and no sets in 348B.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147119 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147119 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147119\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147162\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/01/2013 21:53\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147162\" href=\"?#comment-147162\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147162\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147162\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I get a memory limit on problem Apple Tree. here is my submission : <a href=\"//codeforces.com/contest/348/submission/4630566\">http://codeforces.com/contest/348/submission/4630566</a> Anybody knows why ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147162 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147162 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147162\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147301\" commentParentId=\"147162\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Vadim2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49195/avatar/6b6e0d05659bf599.jpg'/> </a>\n <div><a href=\"/profile/Vadim2\" title=\"Expert Vadim2\" class=\"rated-user user-blue\">Vadim2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/02/2013 23:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147301\" href=\"?#comment-147301\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-147162\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147301\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"49195\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147301\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The leaf of the Apple Tree can be 0. So lcm can be zero.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147301 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147301 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147301\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147248\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/accidentallygivenfuck\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34459/avatar/c4e2278aa2ac1176.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/accidentallygivenfuck\" title=\"Expert accidentallygivenfuck\" class=\"rated-user user-blue\">accidentallygivenfuck</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/02/2013 13:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147248\" href=\"?#comment-147248\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147248\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34459\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147248\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone explain <strong>348A — Mafia</strong> with more details, please? :|</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147248 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147248 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147248\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147355\" commentParentId=\"147248\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Baklazan\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Baklazan\" title=\"International Master Baklazan\" class=\"rated-user user-orange\">Baklazan</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/03/2013 17:44\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147355\" href=\"?#comment-147355\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-147248\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147355\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"12\"\r\n data-commentUserId=\"114840\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+12</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147355\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Let's say you're going to play <span class=\"tex-span\"><i>x</i></span> games. If someone wanted to play more than <span class=\"tex-span\"><i>x</i></span> games, he wouldn't be able to do so, so he would be unhappy. Therefore, if everyone is happy, <span class=\"tex-span\"><i>x</i> ≥ <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> must hold for each <span class=\"tex-span\"><i>i</i></span>, so </p> <center><span class=\"tex-span\"><i>x</i> ≥ <i>max</i>(<i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span></center><p>Let $b_i$ be number of games, where <span class=\"tex-span\"><i>i</i></span>-th player is supervisor and let <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> be number of games, where he plays. In each game <span class=\"tex-span\"><i>i</i></span>-th player is playing, XOR supervising, so <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub> + <i>b</i><sub class=\"lower-index\"><i>i</i></sub> = <i>x</i></span>. Also, he wants to play at least <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> games, so <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>c</i><sub class=\"lower-index\"><i>i</i></sub></span>, thus <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>c</i><sub class=\"lower-index\"><i>i</i></sub> + <i>b</i><sub class=\"lower-index\"><i>i</i></sub> - <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, so <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>x</i> - <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. </p><p>Each game is supervised by one player, so <span class=\"tex-span\"><i>x</i> = <i>b</i><sub class=\"lower-index\">1</sub> + <i>b</i><sub class=\"lower-index\">2</sub> + ... + <i>b</i><sub class=\"lower-index\"><i>n</i></sub></span>. Giving it all together: </p> <center><span class=\"tex-span\"><i>x</i> = <i>b</i><sub class=\"lower-index\">1</sub> + <i>b</i><sub class=\"lower-index\">2</sub> + ... + <i>b</i><sub class=\"lower-index\"><i>n</i></sub> ≤ (<i>x</i> - <i>a</i><sub class=\"lower-index\">1</sub>) + (<i>x</i> - <i>a</i><sub class=\"lower-index\">2</sub>) + ... + (<i>x</i> - <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span></center> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b91018ef94caa7373d61367cc8bd8cf553e99329.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/164a2e2eefd69188dba4005a8ed19ecb5e384047.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>Now we have two lower bounds for $x$ . Smallest <span class=\"tex-span\"><i>x</i></span> satisfying both of them is </p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bcb7ee26b56faf91afcf46c3be4778edaef42c59.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>This number of games is enough, because if first $x - a_1$ games are supervised by first player, next <span class=\"tex-span\"><i>x</i> - <i>a</i><sub class=\"lower-index\">2</sub></span> games are supervised by second player etc., until the <span class=\"tex-span\"><i>x</i></span>-th game, then everyone plays enough games and each game is supervised by someone.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147355 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147355 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147355\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147259\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/logic_max\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6829/avatar/abbf50e9dcdf31d9.jpg'/> </a>\n <div><a href=\"/profile/logic_max\" title=\"Expert logic_max\" class=\"rated-user user-blue\">logic_max</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/02/2013 16:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147259\" href=\"?#comment-147259\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147259\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"6829\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147259\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 348A-Mafia, How does this condition ensures that the value of 'x' found is minimum?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147259 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147259 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147259\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"151234\" commentParentId=\"147259\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/th3_g0d\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49094/avatar/cac2f0ea87059e87.jpg'/> </a>\n <div><a href=\"/profile/th3_g0d\" title=\"Specialist th3_g0d\" class=\"rated-user user-cyan\">th3_g0d</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/18/2013 18:41\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-151234\" href=\"?#comment-151234\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-147259\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"151234\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"151234\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49094\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-151234\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We simple do the binary search. Because of the principle of the binary search. We wouldn't be able to decrease x lower that lower bound in binary search(we checked the lower bound and found it impossible to fulfill the conditions by making only "lower bound" number games), similar for upper bound. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-151234 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-151234 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-151234\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"558137\" commentParentId=\"147259\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/chaudhary_19\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/906095/avatar/69d9a206b703555d.jpg'/> </a>\n <div><a href=\"/profile/chaudhary_19\" title=\"Pupil chaudhary_19\" class=\"rated-user user-green\">chaudhary_19</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/15/2019 20:45\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-558137\" href=\"?#comment-558137\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-147259\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"558137\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"906095\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-558137\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>read discrete binary search from topcoder...you will understand</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-558137 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-558137 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-558137\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147322\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/selfcompiler\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/56985/avatar/df149b92aa5cb4d2.jpg'/> </a>\n <div><a href=\"/profile/selfcompiler\" title=\"Pupil selfcompiler\" class=\"rated-user user-green\">selfcompiler</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/03/2013 10:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147322\" href=\"?#comment-147322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"56985\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can some one explain following line from apple tree editorial. Line : <strong>The value in the leaf is equal to the value in the root divided to the product of the powers of all vertices on the path between root and leaf.</strong> how this come ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147322\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"147347\" commentParentId=\"147322\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/accidentallygivenfuck\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34459/avatar/c4e2278aa2ac1176.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/accidentallygivenfuck\" title=\"Expert accidentallygivenfuck\" class=\"rated-user user-blue\">accidentallygivenfuck</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/03/2013 16:09\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-147347\" href=\"?#comment-147347\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-147322\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"147347\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"34459\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-147347\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>value in a node = weight of a node.<br />power of a node = number of children of a node.<br />Let the value in the parent be X and power of it be K. Then value in each of its children will be X/K, as values of each children needs to be equal. Example:<br />A is the root and D is a leaf.<br />A (weight:X, power:3) --> B (weight:X/3, power:2) --> C (weight:X/(3*2), power:3) --> D (weight:X/(3*2*3)).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-147347 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-147347 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-147347\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"234266\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/VastoLorde95\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/264494/avatar/b603d409c06858e3.jpg'/> </a>\n <div><a href=\"/profile/VastoLorde95\" title=\"Master VastoLorde95\" class=\"rated-user user-orange\">VastoLorde95</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/10/2015 18:53\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-234266\" href=\"?#comment-234266\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"234266\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"264494\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-234266\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div. 1 Problem B, I didn't understand the idea behind d[i]. Why are we taking the lcm of all the children of the i'th vertex? What is the logic behind the solution. Could someone please help me out and elaborate?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-234266 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-234266 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-234266\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"237448\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sophisticated1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/222245/avatar/c6d10fa052948320.jpg'/> </a>\n <div><a href=\"/profile/sophisticated1\" title=\"Expert sophisticated1\" class=\"rated-user user-blue\">sophisticated1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2015 22:21\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-237448\" href=\"?#comment-237448\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"237448\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"222245\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-237448\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone provide a more detailed explanation for Div1 B ??</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-237448 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-237448 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-237448\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"307062\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/25/2016 11:50\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-307062\" href=\"?#comment-307062\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"307062\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-307062\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't know why does my solution for Div1B gets TLE... Can somebody help and take a look at it? Thanks in advance.</p><p><a href=\"//codeforces.com/contest/348/submission/19399532\">http://codeforces.com/contest/348/submission/19399532</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-307062 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-307062 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-307062\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"313440\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Omar_Morsi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/301287/avatar/9a3bfd9ec0110ac7.jpg'/> </a>\n <div><a href=\"/profile/Omar_Morsi\" title=\"Master Omar_Morsi\" class=\"rated-user user-orange\">Omar_Morsi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/03/2016 21:37\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-313440\" href=\"?#comment-313440\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"313440\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"301287\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-313440\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Actually , We can solve Problem <strong>348A-Mafia</strong> in a simpler way. let S = Σ a(i) for all i , c(i) = number of rounds played by the ith person so far , S2 = Σ c(i) for all i.</p><p>Then S2 is the Summation of the number of rounds played by each person so far. Actually , we need the number of Rounds X Which will make S2 >= S holds.</p><p>You Can Notice that after X Rounds , S2 Will be Equal to X*N — X , Were N is the number of People. Because simply , After each Round S2 will be incremented by the number of People -1 because all of them will play except one will be the supervisor.</p><p>So we just need to Search using <strong>Binary Search</strong> on the value X which will make X*N — X >= S holds .</p><p><strong>NOTE</strong> : X should be >= max (a(i)).</p><p>Here is the link for my code.</p><p><a href=\"/contest/348/submission/20368610\" title=\"Посылка 20368610 от Omar_Morsi\">20368610</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-313440 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-313440 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-313440\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"639338\" commentParentId=\"313440\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shivaram_22\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/879212/avatar/876c401d7816827d.jpg'/> </a>\n <div><a href=\"/profile/shivaram_22\" title=\"Expert shivaram_22\" class=\"rated-user user-blue\">shivaram_22</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2020 00:27\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-639338\" href=\"?#comment-639338\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-313440\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"639338\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"879212\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-639338\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Shouldn't we also need for all i (c[i]>=a[i]) after playing X rounds, & how does the condition S2>=S guarantees that</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-639338 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-639338 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-639338\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"443042\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Khaner\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/688693/avatar/383254eac6974dc0.jpg'/> </a>\n <div><a href=\"/profile/Khaner\" title=\"Specialist Khaner\" class=\"rated-user user-cyan\">Khaner</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2018 11:22\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-443042\" href=\"?#comment-443042\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"443042\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"443042\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"688693\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-443042\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem B (div 2) has a tag of DP. how we can implement dp on this problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-443042 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-443042 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-443042\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"508854\" commentParentId=\"443042\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hmrockstar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/322920/avatar/75115102a145728.jpg'/> </a>\n <div><a href=\"/profile/hmrockstar\" title=\"Specialist hmrockstar\" class=\"rated-user user-cyan\">hmrockstar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/01/2019 12:44\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-508854\" href=\"?#comment-508854\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-443042\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"508854\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"322920\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-508854\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/contest/349/submission/53604624\">This</a> may help.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-508854 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-508854 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-508854\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"596791\" commentParentId=\"508854\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_Contender_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/598279/avatar/be945805fe1338ab.jpg'/> </a>\n <div><a href=\"/profile/_Contender_\" title=\"Specialist _Contender_\" class=\"rated-user user-cyan\">_Contender_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/03/2020 11:13\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-596791\" href=\"?#comment-596791\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-508854\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"596791\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"598279\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-596791\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thankyou hmrockstar your solution was great!! </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-596791 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-596791 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-596791\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"524698\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dougalves\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/672324/avatar/3e54931bdff5f8e7.jpg'/> </a>\n <div><a href=\"/profile/dougalves\" title=\"Expert dougalves\" class=\"rated-user user-blue\">dougalves</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/03/2019 21:12\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-524698\" href=\"?#comment-524698\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"524698\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"672324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-524698\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>DIV 2 B has dp tag, but it's a greedy problem :/</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-524698 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-524698 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-524698\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"529485\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AK18\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631454/avatar/822fc09d43fa67a8.jpg'/> </a>\n <div><a href=\"/profile/AK18\" title=\"Expert AK18\" class=\"rated-user user-blue\">AK18</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/23/2019 15:37\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-529485\" href=\"?#comment-529485\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"529485\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"529485\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631454\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-529485\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 B, when we are calculating d[i] we are not considering the children of other nodes of the same level ?? for example, if root has 2 children and one of them has 3 children and another one has 2 children then we need to have the lcm of both 3 and 2 which is 6. please help !!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-529485 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-529485 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-529485\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"584298\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PiasRoY\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/554651/avatar/20d0c41f2221bcd1.jpg'/> </a>\n <div><a href=\"/profile/PiasRoY\" title=\"Specialist PiasRoY\" class=\"rated-user user-cyan\">PiasRoY</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/28/2020 00:51\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-584298\" href=\"?#comment-584298\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"584298\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"554651\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\